Compound, resin, material for forming underlayer film for lithography, composition for forming underlayer film for lithography, underlayer film for lithography, pattern forming method, and method for purifying compound or resin

ABSTRACT

A compound represented by the following formula (1). 
                         
(in formula (1), each X independently represents an oxygen atom, a sulfur atom, or non-crosslinking, each R 1  is independently selected from the group consisting of a hydrogen atom, a halogen group, a nitro group, an amino group, a hydroxyl group, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 40 carbon atoms and combinations thereof, in which the alkyl group, the alkenyl group and the aryl group may have an ether bond, a ketone bond or an ester bond, each R 2  independently represents a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, a thiol group or a hydroxyl group, in which at least one R 2  represents a group having a hydroxyl group or a thiol group, each m is independently an integer of 1 to 7, each p is independently 0 or 1, each q is independently an integer of 0 to 4, and n is 0 or 1.)

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national phase application filed under 35U.S.C. § 371 of International Application PCT/JP2016/057438, filed onMar. 9, 2016, designating the United States, which claims priority fromJapanese Application Number 2015-050731, filed Mar. 13, 2015, which arehereby incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to a compound or a resin having a specificstructure. The present invention also relates to a material for formingan underlayer film for lithography and a composition for forming anunderlayer film for lithography, containing the compound or the resin,an underlayer film for lithography, obtained from the material, and aphotoresist pattern forming method using the material. Furthermore, thepresent invention relates to a method for purifying the compound or theresin.

BACKGROUND Of THE INVENTION

Semiconductor devices are manufactured through microfabrication bylithography using a photoresist material, but are required to be madefiner by a pattern rule in accordance with the increase in integrationdegree and the increase in speed of LSI in recent years. In lithographyusing exposure to light, which is currently used as a general-purposetechnique, the resolution is now approaching the intrinsic limitationassociated with the wavelength of the light source.

A light source for lithography, for use in forming a resist pattern, hasa shorter wavelength from a KrF excimer laser (248 nm) to an ArF excimerlaser (193 nm). However, as the resist pattern is made finer and finer,there arise a problem of resolution and a problem of collapse of theresist pattern after development, and therefore there is demanded formaking a resist film thinner. If the resist film is merely made thinnerin response to such a demand, it is difficult to achieve the resistpattern having a film thickness sufficient for processing a substrate.Accordingly, there is increasingly required a process in which not onlythe resist pattern but also a resist underlayer film is prepared betweena resist and a semiconductor substrate to be processed and the resistunderlayer film is allowed to have a function as a mask at the time ofprocessing the substrate.

Currently, as the resist underlayer film for such a process, variousones are known. Examples can include a resist underlayer film forlithography, having a selection ratio of dry etching rate close to theresist, unlike a conventional resist underlayer film having a highetching rate. As the material for forming such a resist underlayer filmfor lithography, there has been proposed a material for forming anunderlayer film for multilayer resist process, containing a resincomponent having at least a substituent which releases a terminal groupto form a sulfonic acid residue when a predetermined energy is applied,and a solvent (see, for example, Patent Literature 1). In addition,examples can also include a resist underlayer film for lithography,having a smaller selection ratio of dry etching rate than the resist. Asthe material for forming such a resist underlayer film for lithography,there has been proposed a resist underlayer film material including apolymer having a specific repeating unit (see, for example, PatentLiterature 2). Furthermore, examples can include a resist underlayerfilm for lithography, having a smaller selection ratio of dry etchingrate than the semiconductor substrate. As the material for forming sucha resist underlayer film for lithography, there has been proposed aresist underlayer film material including a polymer formed byco-polymerizing a repeating unit of acenaphthylene, and a substituted ornon-substituted repeating unit having a hydroxyl group (see, forexample, Patent Literature 3).

On the other hand, as a material for allowing such a resist underlayerfilm to have a high etching resistance, an amorphous carbon underlayerfilm is well known, which is formed by CVD using methane gas, ethanegas, acetylene gas, or the like as a raw material. However, there isdemanded, in terms of process, a resist underlayer film material thatcan form a resist underlayer film in a wet process such as a spincoating method or screen printing.

In addition, as a material that is excellent in optical characteristicsand etching resistance and that is capable of being dissolved in asolvent and being applied to a wet process, the present inventors haveproposed a composition for forming an underlayer film for lithography,which contains a naphthalene formaldehyde polymer including a specificconstituent unit, and an organic solvent (see, for example, PatentLiteratures 4 and 5).

Meanwhile, with respect to a forming method of an intermediate layer foruse in forming a resist underlayer film in a three-layer process, forexample, known are a forming method of a silicon nitride film (see, forexample, Patent Literature 6), and a CVD forming method of a siliconnitride film (see, for example, Patent Literature 7). In addition, as anintermediate layer material for a three-layer process, known is amaterial containing a silsesquioxane-based silicon compound (see, forexample, Patent Literatures 8 and 9).

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent Laid-Open No. 2004-177668

Patent Literature 2: Japanese Patent Laid-Open No. 2004-271838

Patent Literature 3: Japanese Patent Laid-Open No. 2005-250434

Patent Literature 4: International Publication No. WO 2009/072465

Patent Literature 5: International Publication No. WO 2011/034062

Patent Literature 6: Japanese Patent Laid-Open No. 2002-334869

Patent Literature 7: International Publication No. WO 2004/066377

Patent Literature 8: Japanese Patent Laid-Open No. 2007-226170

Patent Literature 9: Japanese Patent Laid-Open No. 2007-226204

SUMMARY OF INVENTION

As described above, many materials for forming an underlayer film forlithography have been conventionally proposed, but there are no onesthat not only have such a high solvent solubility as to be able to beapplied to a wet process such as a spin coating method or screenprinting, but also simultaneously satisfy heat resistance and etchingresistance at a high level, and thus a new material is required to bedeveloped.

In addition, in recent years, as the pattern has been increasingly madefiner, there have been demanded step embedding properties which enable,even in the case of a substrate having a step (in particular, finespace, hole pattern and the like), a material to be filled uniformly inevery part of the step, and flatness of a film formed. In particular, aresist layer disposed closer to a substrate (an underlayer film) ishighly required to satisfy such demands.

The present invention has been made in view of the above problem, and anobject thereof is to provide a compound, a resin, a material for formingan underlayer film for lithography, a composition including thematerial, a pattern forming method using the material, and apurification method of the compound or the resin, which can be appliedto a wet process in formation of a photoresist underlayer film and whichcan provide an underlayer film for lithography, excellent in heatresistance and etching resistance.

The present inventors have intensively studied to solve the aboveproblem, and as a result, have found that the above problem can besolved by using a compound or a resin having a specific structure,thereby leading to the completion of the present invention.

That is, the present invention is as follows.

[1]

A compound represented by the following formula (1):

wherein each X independently represents an oxygen atom, a sulfur atom,or non-crosslinking, each R¹ is independently selected from the groupconsisting of a hydrogen atom, a halogen group, a nitro group, an aminogroup, a hydroxyl group, an alkyl group having 1 to 30 carbon atoms, analkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 40carbon atoms and combinations thereof, in which the alkyl group, thealkenyl group and the aryl group may have an ether bond, a ketone bondor an ester bond, each R² independently represents a linear, branched orcyclic alkyl group having 1 to 30 carbon atoms, an aryl group having 6to 40 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, athiol group or a hydroxyl group, in which at least one R² represents agroup having a hydroxyl group or a thiol group, each m is independentlyan integer of 1 to 7, each p is independently 0 or 1, each q isindependently an integer of 0 to 4, and n is 0 or 1.

[2]

The compound according to [1], wherein the compound represented by theformula (1) is a compound represented by the following formula (1-1):

wherein R¹, R², m, p, q and n are the same as defined in the formula(1).

[3]

The compound according to [2], wherein the compound represented by theformula (1-1) is a compound represented by the following formula (1-2):

wherein R¹, p, q and n are the same as defined in the formula (1), eachR³ independently represents a linear, branched or cyclic alkyl grouphaving 1 to 30 carbon atoms, an aryl group having 6 to 40 carbon atoms,or an alkenyl group having 2 to 30 carbon atoms, each m² isindependently an integer of 0 to 5, each m³ is independently an integerof 1 to 6, and m²+m³ is an integer of 1 to 6.

[4]

The compound according to [3], wherein the compound represented by theformula (1-2) is a compound represented by the following formula (1-3):

wherein R¹, p, q and n are the same as defined in the formula (1), andR³ and m² are the same as defined in the formula (1-2).

[5]

The compound according to [4], wherein the compound represented by theformula (1-3) is a compound represented by the following formula (1-4):

wherein R¹ and q are the same as defined in the formula (1).

[6]

The compound according to [5], wherein the compound represented by theformula (1-4) is a compound represented by the following formula(CAX-1).

[7]

A resin obtained by using the compound according to any of [1] to [6] asa monomer.

[8]

The resin according to [7], obtained by reacting the compound accordingto any of [1] to [6] with a compound having crosslinking reactivity.

[9]

The resin according to [8], wherein the compound having crosslinkingreactivity is one or more selected from the group consisting ofaldehyde, ketone, carboxylic acid, carboxylic halide, ahalogen-containing compound, an amino compound, an imino compound,isocyanate and an unsaturated hydrocarbon group-containing compound.

[10]

A resin having a structure represented by the following formula (2):

wherein each X independently represents an oxygen atom, a sulfur atom,or non-crosslinking, each R¹ is independently selected from the groupconsisting of a hydrogen atom, a halogen group, a nitro group, an aminogroup, a hydroxyl group, an alkyl group having 1 to 30 carbon atoms, analkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 40carbon atoms and combinations thereof, in which the alkyl group, thealkenyl group and the aryl group may have an ether bond, a ketone bondor an ester bond, each R² independently represents a linear, branched orcyclic alkyl group having 1 to 30 carbon atoms, an aryl group having 6to 40 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, athiol group or a hydroxyl group, in which at least one R² represents agroup having a hydroxyl group or a thiol group, each Y independentlyrepresents a single bond, or a linear or branched alkylene group having1 to 20 carbon atoms, each m is independently an integer of 1 to 6, eachp is independently 0 or 1, each q is independently an integer of 0 to 4,and n is 0 or 1.

[11]

A material for forming an underlayer film for lithography, comprisingthe compound according to any of [1] to [6] and/or the resin accordingto any of [7] to [10].

[12]

A composition for forming an underlayer film for lithography, comprisingthe material for forming the underlayer film for lithography accordingto [11], and a solvent.

[13]

The composition for forming the underlayer film for lithographyaccording to [12], further comprising an acid generating agent.

[14]

The composition for forming the underlayer film for lithographyaccording to [12] or [13], further comprising a crosslinking agent.

[15]

An underlayer film for lithography, formed from the composition forforming the underlayer film for lithography according to any of [12] to[14].

[16]

A resist pattern forming method comprising

step (A-1) of forming an underlayer film on a substrate by using thecomposition for forming the underlayer film for lithography according toany of [12] to [14],

step (A-2) of forming at least one photoresist layer on the underlayerfilm, and

step (A-3) of, after step (A-2), irradiating a predetermined region ofthe photoresist layer with radiation, followed by developing.

[17]

A circuit pattern forming method comprising

step (B-1) of forming an underlayer film on a substrate by using thecomposition for forming the underlayer film for lithography according toany of [12] to [14],

step (B-2) of forming an intermediate layer film on the underlayer filmby using a silicon atom-containing resist intermediate layer filmmaterial,

step (B-3) of forming at least one photoresist layer on the intermediatelayer film,

step (B-4) of, after step (B-3), irradiating a predetermined region ofthe photoresist layer with radiation, followed by developing to form aresist pattern, and

step (B-5) of, after step (B-4), etching the intermediate layer filmwith the resist pattern as a mask, etching the underlayer film with theobtained intermediate layer film pattern as an etching mask and etchingthe substrate with the obtained underlayer film pattern as an etchingmask, to form a pattern on the substrate.

[18]

A method for purifying the compound according to any of [1] to [6] orthe resin according to any of [7] to [10], the method comprising

a step of bringing a solution comprising an organic solvent optionallyimmiscible with water and the compound or the resin into contact with anacidic aqueous solution for extraction.

[19]

The method according to [18], wherein the acidic aqueous solution is anaqueous solution of at least one mineral acid selected from the groupconsisting of hydrochloric acid, sulfuric acid, nitric acid andphosphoric acid, or an aqueous solution of at least one organic acidselected from the group consisting of acetic acid, propionic acid,oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid,tartaric acid, citric acid, methanesulfonic acid, phenolsulfonic acid,p-toluenesulfonic acid and trifluoroacetic acid.

[20]

The method according to [18] or [19], wherein the organic solventoptionally immiscible with water is toluene, 2-heptanone, cyclohexanone,cyclopentanone, methyl isobutyl ketone, propylene glycol monomethylether acetate, 1,2-diethoxyketone, butyl acetate or ethyl acetate.

[21]

The method according to any of [18] to [20], further comprising a stepof performing an extraction treatment with water, after the step ofbringing the solution into contact with the acidic aqueous solution forextraction.

According to the present invention, it is possible to provide a materialfor forming an underlayer film for lithography, which can be applied toa wet process and which can provide an underlayer film for lithography,excellent in heat resistance and etching resistance.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment (hereinafter, referred to as “the presentembodiment”) of the present invention will be described. It is to benoted that the present embodiments are illustrative for describing thepresent invention, and the present invention is not limited only to thepresent embodiments.

[Compound]

A compound of the present embodiment is represented by the followingformula (1). The compound of the present embodiment has such aconfiguration, and therefore can be applied to a wet process information of a photoresist underlayer film and is excellent in heatresistance and etching resistance. In addition, the compound of thepresent embodiment has a specific structure, and therefore has a highheat resistance and also a high solvent solubility. Therefore, thecompound of the present embodiment can be used to form an underlayerfilm whose degradation is suppressed at high-temperature baking, whichis also excellent in etching resistance to oxygen plasma etching or thelike, and which is excellent in embedding properties in a steppedsubstrate, and film flatness. Furthermore, the compound is alsoexcellent in adhesiveness with a resist layer and therefore can form anexcellent resist pattern.

In the formula (1), each X independently represents an oxygen atom, asulfur atom, or non-crosslinking.

Each R¹ is independently selected from the group consisting of ahydrogen atom, a halogen group, a nitro group, an amino group, ahydroxyl group, an alkyl group having 1 to 30 carbon atoms, an alkenylgroup having 2 to 30 carbon atoms, an aryl group having 6 to 40 carbonatoms and combinations thereof, in which the alkyl group, the alkenylgroup and the aryl group may have an ether bond, a ketone bond or anester bond.

Examples of the halogen group include, but not limited to the following,a fluoro group, a chloro group, a bromo group and an iodo group.

Examples of the alkyl group having 1 to 30 carbon atoms include, but notlimited to the following, a methyl group, an ethyl group, a n-propylgroup, an i-propyl group, a cyclopropyl group, a n-butyl group, ani-butyl group, a s-butyl group, a t-butyl group, a cyclobutyl group, a1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, a n-pentylgroup, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a1-ethyl-n-propyl group, a cyclopentyl group, a 1-methyl-cyclobutylgroup, a 2-methyl-cyclobutyl group, a 3-methyl-cyclobutyl group, a1,2-dimethyl-cyclopropyl group, a 2,3-dimethyl-cyclopropyl group, a1-ethyl-cyclopropyl group, a 2-ethyl-cyclopropyl group, a n-hexyl group,a 1-methyl-n-pentyl group, a 2-methyl-n-pentyl group, a3-methyl-n-pentyl group, a 4-methyl-n-pentyl group, a1,1-dimethyl-n-butyl group, a 1,2-dimethyl-n-butyl group, a1,3-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a2,3-dimethyl-n-butyl group, a 3,3-dimethyl-n-butyl group, a1-ethyl-n-butyl group, a 2-ethyl-n-butyl group, a1,1,2-trimethyl-n-propyl group, a 1,2,2-trimethyl-n-propyl group, a1-ethyl-1-methyl-n-propyl group, a 1-ethyl-2-methyl-n-propyl group, acyclohexyl group, a 1-methyl-cyclopentyl group, a 2-methyl-cyclopentylgroup, a 3-methyl-cyclopentyl group, a 1-ethyl-cyclobutyl group, a2-ethyl-cyclobutyl group, a 3-ethyl-cyclobutyl group, a1,2-dimethyl-cyclobutyl group, a 1,3-dimethyl-cyclobutyl group, a2,2-dimethyl-cyclobutyl group, a 2,3-dimethyl-cyclobutyl group, a2,4-dimethyl-cyclobutyl group, a 3,3-dimethyl-cyclobutyl group, a1-n-propyl-cyclopropyl group, a 2-n-propyl-cyclopropyl group, a1-i-propyl-cyclopropyl group, a 2-i-propyl-cyclopropyl group, a1,2,2-trimethyl-cyclopropyl group, a 1,2,3-trimethyl-cyclopropyl group,a 2,2,3-trimethyl-cyclopropyl group, a 1-ethyl-2-methyl-cyclopropylgroup, a 2-ethyl-1-methyl-cyclopropyl group,2-ethyl-2-methyl-cyclopropyl group and a 2-ethyl-3-methyl-cyclopropylgroup.

Examples of the alkenyl group having 2 to 30 carbon atoms include, butnot limited to the following, an ethenyl group, a 1-propenyl group, a2-propenyl group, a 1-methyl-1-ethenyl group, a 1-butenyl group, a2-butenyl group, a 3-butenyl group, a 2-methyl-1-propenyl group, a2-methyl-2-propenyl group, a 1-ethylethenyl group, a 1-methyl-1-propenylgroup, a 1-methyl-2-propenyl group, a 1-pentenyl group, a 2-pentenylgroup, a 3-pentenyl group, a 4-pentenyl group, a 1-n-propylethenylgroup, a 1-methyl-1-butenyl group, a 1-methyl-2-butenyl group, a1-methyl-3-butenyl group, a 2-ethyl-2-propenyl group, a2-methyl-1-butenyl group, a 2-methyl-2-butenyl group, a2-methyl-3-butenyl group, a 3-methyl-1-butenyl group, a3-methyl-2-butenyl group, a 3-methyl-3-butenyl group, a1,1-dimethyl-2-propenyl group, a 1-i-propylethenyl group, a1,2-dimethyl-1-propenyl group, a 1,2-dimethyl-2-propenyl group, a1-cyclopentenyl group, a 2-cyclopentenyl group, a 3-cyclopentenyl group,a 1-hexenyl group, a 2-hexenyl group, a 3-hexenyl group, a 4-hexenylgroup, 5-hexenyl group, a 1-methyl-1-pentenyl group, a1-methyl-2-pentenyl group, a 1-methyl-3-pentenyl group, a1-methyl-4-pentenyl group, a 1-n-butylethenyl group, a2-methyl-1-pentenyl group, a 2-methyl-2-pentenyl group, a2-methyl-3-pentenyl group, a 2-methyl-4-pentenyl group, a2-n-propyl-2-propenyl group, a 3-methyl-1-pentenyl group, a3-methyl-2-pentenyl group, a 3-methyl-3-pentenyl group, a3-methyl-4-pentenyl group, a 3-ethyl-3-butenyl group, a4-methyl-1-pentenyl group, a 4-methyl-2-pentenyl group, a4-methyl-3-pentenyl group, a 4-methyl-4-pentenyl group, a1,1-dimethyl-2-butenyl group, a 1,1-dimethyl-3-butenyl group, a1,2-dimethyl-1-butenyl group, a 1,2-dimethyl-2-butenyl group, a1,2-dimethyl-3-butenyl group, a 1-methyl-2-ethyl-2-propenyl group, a1-s-butylethenyl group, a 1,3-dimethyl-1-butenyl group, a1,3-dimethyl-2-butenyl group, a 1,3-dimethyl-3-butenyl group, a1-i-butylethenyl group, a 2,2-dimethyl-3-butenyl group, a2,3-dimethyl-1-butenyl group, a 2,3-dimethyl-2-butenyl group, a2,3-dimethyl-3-butenyl group, a 2-i-propyl-2-propenyl group, a3,3-dimethyl-1-butenyl group, a 1-ethyl-1-butenyl group, a1-ethyl-2-butenyl group, a 1-ethyl-3-butenyl group, a1-n-propyl-1-propenyl group, a 1-n-propyl-2-propenyl group, a2-ethyl-1-butenyl group, a 2-ethyl-2-butenyl group, a 2-ethyl-3-butenylgroup, a 1,1,2-trimethyl-2-propenyl group, a 1-t-butylethenyl group, a1-methyl-1-ethyl-2-propenyl group, a 1-ethyl-2-methyl-1-propenyl group,a 1-ethyl-2-methyl-2-propenyl group, a 1-i-propyl-1-propenyl group, a1-i-propyl-2-propenyl group, a 1-methyl-2-cyclopentenyl group, a1-methyl-3-cyclopentenyl group, a 2-methyl-1-cyclopentenyl group, a2-methyl-2-cyclopentenyl group, a 2-methyl-3-cyclopentenyl group, a2-methyl-4-cyclopentenyl group, a 2-methyl-5-cyclopentenyl group, a2-methylene-cyclopentyl group, a 3-methyl-1-cyclopentenyl group, a3-methyl-2-cyclopentenyl group, a 3-methyl-3-cyclopentenyl group, a3-methyl-4-cyclopentenyl group, a 3-methyl-5-cyclopentenyl group, a3-methylene-cyclopentyl group, a 1-cyclohexenyl group, a 2-cyclohexenylgroup and a 3-cyclohexenyl group.

Examples of the aryl group having 6 to 40 carbon atoms include, but notlimited to the following, a phenyl group, an o-methylphenyl group, am-methylphenyl group, a p-methylphenyl group, an o-chlorophenyl group, am-chlorophenyl group, a p-chlorophenyl group, an o-fluorophenyl group, ap-fluorophenyl group, an o-methoxyphenyl group, a p-methoxyphenyl group,a p-nitrophenyl group, a p-cyanophenyl group, an α-naphthyl group, aβ-naphthyl group, an o-biphenyl group, a m-biphenyl group, a p-biphenylgroup, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a4-phenanthryl group and a 9-phenanthryl group.

Each R² independently represents a linear, branched or cyclic alkylgroup having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbonatoms, an alkenyl group having 2 to 30 carbon atoms, a thiol group or ahydroxyl group, in which at least one R² represents a group having ahydroxyl group or a thiol group. Herein, examples of the group having ahydroxyl group include, but not limited to the following, a hydroxylgroup, a linear, branched or cyclic alkyl group having 1 to 30 carbonatoms, substituted with a hydroxyl group, an aryl group having 6 to 40carbon atoms, substituted with a hydroxyl group, and an alkenyl grouphaving 2 to 30 carbon atoms, substituted with a hydroxyl group. Inaddition, examples of the group having a thiol group include, but notlimited to the following, a thiol group, a linear, branched or cyclicalkyl group having 1 to 30 carbon atoms, substituted with a thiol group,an aryl group having 6 to 40 carbon atoms, substituted with a thiolgroup, and an alkenyl group having 2 to 30 carbon atoms, substitutedwith a thiol group.

Examples of the alkyl group having 1 to 30 carbon atoms, the alkenylgroup having 2 to 30 carbon atoms, and the aryl group having 6 to 40carbon atoms include those exemplified with respect to R¹ describedabove.

Each m is independently an integer of 1 to 7, each p is independently 0or 1, each q is independently an integer of 0 to 4, and n is 0 or 1.

The compound represented by the formula (1) has a high heat resistancedue to rigidity of its structure while having a relatively low molecularweight, and therefore it can be used even under a high-temperaturebaking condition. In addition, the compound has a relatively lowmolecular weight and a low viscosity, and therefore, even when beingapplied to a substrate having a step (in particular, fine space, holepattern and the like), it can be easily filled uniformly in every partof the step. As a result, a material for forming an underlayer film forlithography using such a compound can be improved in terms of embeddingproperties in a relatively advantageous manner. In addition, thecompound imparts also a high etching resistance. Herein, the molecularweight of the compound of the present embodiment is preferably 400 to3000, more preferably 400 to 2000, further preferably 400 to 1000.Herein, the molecular weight can be measured by a method in Examplesdescribed later.

In the compound represented by the formula (1), at least one R² has ahydroxyl group or a thiol group in terms of ease of crosslinking andsolubility in an organic solvent.

The compound represented by the formula (1) is preferably a compoundrepresented by the following formula (1-1) in terms of the supply of rawmaterials.

In the formula (1-1), R¹, R², m, p, q and n are the same as defined inthe formula (1).

The compound represented by the formula (1-1) is more preferably acompound represented by the following formula (1-2) in terms ofsolubility in an organic solvent.

In the formula (1-2), R¹, p, q and n are the same as defined in theformula (1), each R³ independently represents a linear, branched orcyclic alkyl group having 1 to 30 carbon atoms, an aryl group having 6to 40 carbon atoms, or an alkenyl group having 2 to 30 carbon atoms,each m² is independently an integer of 0 to 5, each m³ is independentlyan integer of 1 to 6, and m²+m³ is independently an integer of 1 to 6.

The compound represented by the formula (1-2) is further preferably acompound represented by the following formula (1-3) in terms of furthersolubility in an organic solvent.

In the formula (1-3), R¹, R², p, q and n are the same as defined in theformula (1), and R³ and m² are the same as defined in the formula (1-2).

The compound represented by the formula (1-3) is further more preferablya mode in which n=1 in the formula (1-3), namely, a compound representedby the following formula (1-4), from the viewpoint that one having alower molecular weight is better in fluidity.

In the formula (1-4), R¹ and q are the same as defined in the formula(1).

Furthermore, the compound represented by the general formula (1-4) isfurther preferably a compound represented by the following formula(CAX-1) in terms of ease of production and the supply of raw materials.

Hereinafter, specific examples of the compound represented by theformula (1) are shown, but are not limited to those recited herein.

In the above compound, R¹, R², q and m are the same as defined in theformula (1).

In the above compound, R¹, R² and m are the same as defined in theformula (1), and q is an integer of 0 to 3.

In the present embodiment, the compound represented by the formula (1)can be appropriately synthesized by applying a known method, and asynthesis method thereof is not particularly limited. For example,phenols, thiophenols, naphthols or thionaphthols and the correspondingaldehydes can be subjected to a polycondensation reaction under ordinarypressure in the presence of an acid catalyst to thereby provide thecompound represented by the formula (1). The reaction can also beperformed under pressure, if necessary.

Examples of the phenols include phenol, methyl phenol, methoxybenzene,catechol, hydroquinone and trimethylhydroquinone, but are not limitedthereto. These can be used singly or in combinations of two or morethereof. Among them, hydroquinone and trimethylhydroquinone arepreferably used from the viewpoint that a xanthene structure can beeasily made.

Examples of the thiophenols include benzenethiol, methylbenzenethiol,methoxybenzenethiol, benzenedithiol and trimethylbenzenedithiol, but arenot limited thereto. These can be used singly or in combinations of twoor more thereof. Among them, benzenedithiol and trimethylbenzenedithiolare preferably used from the viewpoint that a thioxanthene structure canbe easily made.

Examples of the naphthols include naphthol, methylnaphthol,methoxynaphthol and naphthalenediol, but are not limited thereto. Thesecan be used singly or in combinations of two or more thereof. Amongthem, naphthalenediol is preferably used from the viewpoint that abenzoxanthene structure can be easily made.

Examples of the thionaphthols include naphthalenethiol,methylnaphthalenethiol, methoxynaphthalenethiol and naphthalenedithiol,but are not limited thereto. These can be used singly or in combinationsof two or more thereof. Among them, naphthalenedithiol is preferablyused from the viewpoint that a thiobenzoxanthene structure can be easilymade.

Examples of the aldehydes include carbazole-3-carbaldehyde,N-methylcarbazole-3-carbaldehyde, N-ethylcarbazole-3-carbaldehyde,N-propylcarbazole-3-carbaldehyde, N-(t-butyl)carbazole-3-carbaldehyde,N-hydroxyethylcarbazole-3-carbaldehyde,N-cyclohexylcarbazole-3-carbaldehyde, N-phenylcarbazole-3-carbaldehyde,N-(4-methylphenyl)carbazole-3-carbaldehyde,N-(4-ethylphenyl)carbazole-3-carbaldehyde,N-(4-methoxyphenyl)carbazole-3-carbaldehyde,N-(3-methoxyphenyl)carbazole-3-carbaldehyde,N-(4-ethoxyphenyl)carbazole-3-carbaldehyde,N-(3-ethoxyphenyl)carbazole-3-carbaldehyde,N-(4-hydroxyphenyl)carbazole-3-carbaldehyde,N-(3-hydroxyphenyl)carbazole-3-carbaldehyde,N-benzylcarbazole-3-carbaldehyde, N-biphenylcarbazole-3-carbaldehyde,N-(4-hydroxybiphenyl)carbazole-3-carbaldehyde,1,4-dimethyl-9H-carbazole-3-carbaldehyde,6-methoxy-1,4-dimethyl-9H-carbazole-3-carbaldehyde,N-nitrosocarbazole-3-carbaldehyde, carbazole-3,6-dicarbaldehyde,N-methylcarbazole-3,6-dicarbaldehyde,N-ethylcarbazole-3,6-dicarbaldehyde,N-propylcarbazole-3,6-dicarbaldehyde,N-(t-butyl)carbazole-3,6-dicarbaldehyde,N-hydroxyethylcarbazole-3,6-dicarbaldehyde,N-cyclohexylcarbazole-3,6-dicarbaldehyde,N-phenylcarbazole-3,6-dicarbaldehyde,N-(4-methylphenyl)carbazole-3,6-dicarbaldehyde,N-(4-ethylphenyl)carbazole-3,6-dicarbaldehyde,N-(4-methoxyphenyl)carbazole-3,6-dicarbaldehyde,N-(3-methoxyphenyl)carbazole-3,6-dicarbaldehyde,N-(4-ethoxyphenyl)carbazole-3,6-dicarbaldehyde,N-(3-ethoxyphenyl)carbazole-3,6-dicarbaldehyde,N-(4-hydroxyphenyl)carbazole-3,6-dicarbaldehyde,N-(3-hydroxyphenyl)carbazole-3,6-dicarbaldehyde,N-benzylcarbazole-3,6-dicarbaldehyde,N-biphenylcarbazole-3,6-dicarbaldehyde,N-(4-hydroxybiphenyl)carbazole-3,6-dicarbaldehyde,1,4-dimethyl-9H-carbazole-3,6-dicarbaldehyde andN-nitrosocarbazole-3,6-dicarbaldehyde, but are not limited thereto.These can be used singly or in combinations of two or more thereof.Among them, N-ethylcarbazole-3-carbaldehyde andN-hydroxyethylcarbazole-3-carbaldehyde are preferably used from theviewpoint of imparting a high solubility and a high heat resistance.

The acid catalyst for use in the above reaction can be appropriatelyselected from known ones and used, and is not particularly limited. Suchan acid catalyst is an inorganic acid or an organic acid, as widelyknown, and examples thereof include inorganic acids such as hydrochloricacid, sulfuric acid, phosphoric acid, hydrobromic acid, or hydrofluoricacid, organic acids such as oxalic acid, malonic acid, succinic acid,adipic acid, sebacic acid, citric acid, fumaric acid, maleic acid,formic acid, p-toluenesulfonic acid, methanesulfonic acid,trifluoroacetic acid, dichloroacetic acid, trichloroacetic acid,trifluoromethanesulfonic acid, benzenesulfonic acid, naphthalenesulfonicacid, or naphthalenedisulfonic acid, Lewis acids such as zinc chloride,aluminum chloride, iron chloride, or boron trifluoride, or solid acidssuch as tungstosilicic acid, tungstophosphoric acid, silicomolybdicacid, or phosphomolybdic acid, but are not limited thereto. Among them,organic acids and solid acids are preferable in terms of production, andhydrochloric acid or sulfuric acid is more preferably used in terms ofproduction such as availability or handleability. Herein, these acidcatalysts can be used alone, or two or more thereof can be used incombination. In addition, the amount of the acid catalyst to be used canbe appropriately set depending on the types of raw materials to be usedand the catalyst to be used, reaction conditions, and the like, and isnot particularly limited, but the amount is preferably 0.01 to 100 partsby mass based on 100 parts by mass of reaction raw materials.

A reaction solvent may also be used during the above reaction. Thereaction solvent that can be used is not particularly limited and isappropriately selected from known ones, as long as the reaction of thealdehydes to be used and the phenols, thiophenols, naphthols orthionaphthols to be used progresses, and examples thereof include water,methanol, ethanol, propanol, butanol, tetrahydrofuran, dioxane, ethyleneglycol dimethyl ether, ethylene glycol diethyl ether, or a mixed solventthereof. Herein, these solvents can be used alone, or two or morethereof can be used in combination. In addition, the amount of thesolvent to be used can be appropriately set depending on the types ofraw materials to be used and the catalyst to be used, reactionconditions, and the like, and is not particularly limited, but theamount is preferably 0 to 2000 parts by mass based on 100 parts by massof reaction raw materials. Furthermore, the reaction temperature in theabove reaction can be appropriately selected depending on the reactivityof reaction raw materials, and is not particularly limited, but thereaction temperature usually ranges from 10 to 200° C.

In order to obtain the compound represented by the general formula (1)of the present embodiment, the reaction temperature is preferably highand, specifically, preferably ranges from 60 to 200° C. Herein, thereaction method that can be used is appropriately selected from knownmethods, and is not particularly limited, but includes a method in whichthe phenols, thiophenols, naphthols or thionaphthols, the aldehydes, andthe catalyst are charged at once, and a method in which the phenols,thiophenols, naphthols or thionaphthols, and the aldehydes or ketonesare dropped in the presence of the catalyst. After completion of thepolycondensation reaction, the resulting compound can be isolatedaccording to an ordinary method, and the isolation method is notparticularly limited. For example, in order to remove the unreacted rawmaterials and the catalyst present in the system, a common method inwhich the temperature in a reaction tank is raised to 130 to 230° C. toremove a volatile content at about 1 to 50 mmHg can be adopted tothereby provide an objective compound.

The reaction progresses under a preferable reaction condition in which 1mol to an excess amount of the phenols, thiophenols, naphthols orthionaphthols and 0.001 to 1 mol of the acid catalyst are used based on1 mol of the aldehydes at ordinary pressure and at 50 to 150° C. forabout 20 minutes to 100 hours.

After completion of the reaction, the objective compound can be isolatedby a known method. For example, the objective compound, the compoundrepresented by the general formula (1), can be obtained by concentratinga reaction liquid, adding pure water thereto to precipitate a reactionproduct, cooling the resultant to room temperature followed byfiltration for separation, drying a solid obtained by filtration, thenseparating the solid into the reaction product and a by-product forpurification by column chromatography, and performing distilling off ofthe solvent, filtration and drying.

[Resin]

A resin of the present embodiment is a resin obtained by using thecompound represented by the formula (1) as a monomer. The resin of thepresent embodiment has a structure represented by formula (2).

In formula (2), each X independently represents an oxygen atom, a sulfuratom, or non-crosslinking.

Each R¹ is independently selected from the group consisting of ahydrogen atom, a halogen group, a nitro group, an amino group, ahydroxyl group, an alkyl group having 1 to 30 carbon atoms, an alkenylgroup having 2 to 30 carbon atoms, an aryl group having 6 to 40 carbonatoms and combinations thereof, in which the alkyl group, the alkenylgroup and the aryl group may have an ether bond, a ketone bond or anester bond.

Each R² independently represents a linear, branched or cyclic alkylgroup having 1 to 30 carbon atoms, an aryl group having 6 to 40 carbonatoms, an alkenyl group having 2 to 30 carbon atoms, a thiol group or ahydroxyl group, in which at least one R² represents a group having ahydroxyl group or a thiol group. Herein, examples of the group having ahydroxyl group include, but not limited to the following, a hydroxylgroup, a linear, branched or cyclic alkyl group having 1 to 30 carbonatoms, substituted with a hydroxyl group, an aryl group having 6 to 40carbon atoms, substituted with a hydroxyl group, and an alkenyl grouphaving 2 to 30 carbon atoms, substituted with a hydroxyl group. Inaddition, examples of the group having a thiol group include, but notlimited to the following, a thiol group, a linear, branched or cyclicalkyl group having 1 to 30 carbon atoms, substituted with a thiol group,an aryl group having 6 to 40 carbon atoms, substituted with a thiolgroup, and an alkenyl group having 2 to 30 carbon atoms, substitutedwith a thiol group.

Each Y independently represents a single bond, or a linear or branchedalkylene group having 1 to 20 carbon atoms.

Each m is independently an integer of 1 to 6, each p is independently 0or 1, each q is independently an integer of 0 to 4, and n is 0 or 1.

The resin having the structure represented by formula (2), to be used inthe present embodiment, is obtained by, for example, reacting thecompound represented by the formula (1) with a compound havingcrosslinking reactivity.

The compound having crosslinking reactivity is not particularly limitedas long as it can provide an oligomer or a polymer of the compoundrepresented by the formula (1), and known one can be used therefor.Specific examples thereof include, for example, aldehyde, ketone,carboxylic acid, carboxylic halide, a halogen-containing compound, anamino compound, an imino compound, isocyanate, and an unsaturatedhydrocarbon group-containing compound, but are not limited thereto.

Specific examples of the resin having the structure represented byformula (2) include, but not limited to the following, a novolac resinobtained by a condensation reaction of the compound represented by theformula (1) with an aldehyde as the monomer having crosslinkingreactivity.

Herein, examples of the aldehyde for use in forming the novolac resin ofthe compound represented by the formula (1) include formaldehyde,trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde,phenylacetaldehyde, phenylpropylaldehyde, hydroxybenzaldehyde,chlorobenzaldehyde, nitrobenzaldehyde, methylbenzaldehyde,ethylbenzaldehyde, butylbenzaldehyde, biphenylaldehyde, naphthaldehyde,anthracenecarbaldehyde, phenanthrenecarbaldehyde, pyrenecarbaldehyde,and furfural, but are not limited thereto. Among them, formaldehyde ismore preferable. Herein, these aldehydes can be used alone, or two ormore thereof can be used in combination. In addition, the amount of thealdehydes to be used is not particularly limited, but the amount ispreferably 0.2 to 5 mol and more preferably 0.5 to 2 mol, based on 1 molof the compound represented by the formula (1).

A reaction solvent can also be used in a condensation reaction of thecompound represented by the formula (1) and the aldehyde. The reactionsolvent that can be used in the polycondensation is not particularlylimited and is appropriately selected from known ones, and examplesthereof include water, methanol, ethanol, propanol, butanol,tetrahydrofuran, dioxane, or a mixed solvent thereof. Herein, thesesolvents can be used alone, or two or more thereof can be used incombination.

In addition, the amount of the solvent to be used can be appropriatelyset depending on the types of raw materials to be used and the catalystto be used, reaction conditions, and the like, and is not particularlylimited, but the amount preferably ranges from 0 to 2000 parts by massbased on 100 parts by mass of reaction raw materials. Furthermore, thereaction temperature can be appropriately selected depending on thereactivity of reaction raw materials, and is not particularly limited,but the reaction temperature usually ranges from 10 to 200° C. Herein,the reaction method that can be used is appropriately selected fromknown methods, and is not particularly limited, but includes a method inwhich the compound represented by the formula (1), the aldehydes, andthe catalyst are charged at once, and a method in which the compoundrepresented by the formula (1) and the aldehydes are dropped in thepresence of the catalyst.

After completion of the polycondensation reaction, the resultingcompound can be isolated according to an ordinary method, and theisolation method is not particularly limited. For example, in order toremove the unreacted raw materials and the catalyst present in thesystem, a common method in which the temperature in a reaction tank israised to 130 to 230° C. to remove a volatile content at about 1 to 50mmHg can be adopted to thereby provide an objective novolac resin.

Herein, the resin of the present embodiment may be a homopolymer of thecompound represented by the formula (1), or may be a copolymer thereofwith other phenols. Examples of the copolymerizable phenols includephenol, cresol, dimethylphenol, trimethylphenol, butylphenol,phenylphenol, diphenylphenol, naphthylphenol, resorcinol,methylresorcinol, catechol, butylcatechol, methoxyphenol, methoxyphenol,propylphenol, pyrogallol, and thymol, but are not limited thereto.

In addition, the resin of the present embodiment may be one obtained bycopolymerization with a polymerizable monomer other than theabove-described other phenols. Examples of such a copolymerizablemonomer include naphthol, methylnaphthol, methoxynaphthol,dihydroxynaphthalene, indene, hydroxyindene, benzofuran,hydroxyanthracene, acenaphthylene, biphenyl, bisphenol, trisphenol,dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norbornadiene,vinylnorbornaene, pinene, and limonene, but are not limited thereto.Herein, the resin of the present embodiment may be a bi or higherfunctional (for example, bi to tetra) copolymer of the compoundrepresented by the formula (1) with the above-described phenols, may bea bi or higher functional (for example, bi to tetra) copolymer of thecompound represented by the formula (1) with the above-describedcopolymerizable monomer, or may be a ter or higher (for example, ter totetra) copolymer of the compound represented by the formula (1), theabove-described phenols, and the above-described copolymerizablemonomer.

Herein, the molecular weight of the resin of the present embodiment isnot particularly limited, and the weight average molecular weight (Mw)in terms of polystyrene is preferably 500 to 20,000, and more preferably750 to 10,000. In addition, the resin of the present embodimentpreferably has a dispersity (weight average molecular weight Mw/numberaverage molecular weight Mn) in a range from 1.1 to 7 from theviewpoints of improving a crosslinking efficiency and suppressing avolatile component during baking. Herein, the Mn can be determined by amethod in Examples described later.

The compound represented by the formula (1) and/or the resin obtained byusing the compound as a monomer preferably have/has a high solubility inthe solvent from the viewpoint of making the application of a wetprocess easier. More specifically, when the solvent is1-methoxy-2-propanol (PGME) and/or propylene glycol monomethyl etheracetate (PGMEA), such a compound and/or resin preferably have/has asolubility of 10% by mass or more in the solvent. Herein, the solubilityin PGME and/or PGMEA is defined as “Mass of resin/(Mass of resin+Mass ofsolvent)×100 (% by mass)”. For example, in the case where 10 g of thecompound represented by the formula (1) and/or the resin obtained byusing the compound as a monomer are/is evaluated to be dissolved in 90 gof PGMEA, the solubility of the compound represented by the formula (1)and/or the resin obtained by using the compound as a monomer in PGMEA is“10% by mass or more”, and in the case where the compound and/or theresin are/is evaluated not to be dissolved, the solubility is “less than10% by mass”.

[Material for Forming Underlayer Film for Lithography]

A material for forming an underlayer film for lithography of the presentembodiment contains at least one substance selected from the groupconsisting of the compound represented by the formula (1) and the resinobtained by using the compound as a monomer. In the present embodiment,the content of the substance in the material for forming an underlayerfilm for lithography is preferably 1 to 100% by mass, more preferably 10to 100% by mass, further preferably 50 to 100% by mass, further morepreferably 100% by mass in terms of coatability and quality stability.

Herein, the material for forming an underlayer film for lithography ofthe present embodiment may include a known material for forming anunderlayer film for lithography, or the like as long as the effect ofthe present embodiment is not impaired.

As described above, the material for forming an underlayer film forlithography of the present embodiment contains at least the compound orthe resin of the present embodiment. The material for forming anunderlayer film for lithography of the present embodiment has such aconfiguration, and therefore can be applied to a wet process and isexcellent in heat resistance and etching resistance. Furthermore, sincethe material for forming an underlayer film for lithography of thepresent embodiment is formed using the compound or the resin, thematerial can be used to form an underlayer film whose degradation issuppressed at high-temperature baking and which is also excellent inetching resistance to oxygen plasma etching or the like. Furthermore,the material for forming an underlayer film for lithography of thepresent embodiment is also excellent in adhesiveness with a resist layerand therefore can form an excellent resist pattern.

[Composition for Forming Underlayer Film for Lithography]

A composition for forming an underlayer film for lithography of thepresent embodiment contains a solvent other than the compoundrepresented by the formula (1) and/or the resin obtained by using thecompound as a monomer. The composition for forming an underlayer filmfor lithography of the present embodiment may contain, if necessary, acrosslinking agent, an acid generating agent, and other component.Hereinafter, the solvent and these optional components will bedescribed.

[Solvent]

The composition for forming an underlayer film for lithography of thepresent embodiment may contain a solvent. The solvent is notparticularly limited and a known solvent can be appropriately used aslong as it dissolves at least the compound represented by the formula(1) and/or the resin obtained by using the compound as a monomer.

Specific examples of the solvent include ketone-based solvents such asacetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone;cellosolve-based solvents such as propylene glycol monomethyl ether andpropylene glycol monomethyl ether acetate; ester-based solvents such asethyl lactate, methyl acetate, ethyl acetate, butyl acetate, isoamylacetate, ethyl lactate, methyl methoxypropionate and methylhydroxyisobutyrate; alcohol-based solvents such as methanol, ethanol,isopropanol and 1-ethoxy-2-propanol; and aromatic hydrocarbons such astoluene, xylene and anisole, but are not limited thereto. These solventscan be used singly or in combinations of two or more thereof.

Among the solvents, preferable are cyclohexanone, propylene glycolmonomethyl ether, propylene glycol monomethyl ether acetate, ethyllactate, methyl hydroxyisobutyrate, and anisole, in terms of safety.

The content of the solvent is not particularly limited, but it ispreferably 100 to 10,000 parts by mass, more preferably 200 to 5,000parts by mass, further preferably 200 to 1,000 parts by mass, based on100 parts by mass of the material for forming an underlayer film, interms of solubility and film formation.

[Crosslinking Agent]

The composition for forming an underlayer film for lithography of thepresent embodiment may contain, if necessary, a crosslinking agent fromthe viewpoint of suppression of intermixing, and the like. Specificexamples of the crosslinking agent usable in the present embodimentinclude a melamine compound, a guanamine compound, a glycolurilcompound, a urea compound, an epoxy compound, a thioepoxy compound, anisocyanate compound, an azide compound, and a compound including adouble bond such as an alkenyl ether group, these compounds beingsubstituted with at least one group selected from a methylol group, analkoxymethyl group and an acyloxymethyl group, as a substituent(crosslinkable group), but are not limited thereto. Herein, thesecrosslinking agents can be used singly or in combinations of two or morethereof. Such a crosslinking agent can also be used as an additive.Herein, the crosslinkable group may also be introduced as a pendantgroup into a polymer side chain of the compound represented by theformula (1) and/or the resin obtained by using the compound as amonomer. A compound including a hydroxyl group can also be used as thecrosslinking agent.

Specific examples of the melamine compound include, but are not limitedto the following, hexamethylolmelamine, hexamethoxymethylmelamine, acompound in which 1 to 6 methylol groups in hexamethylolmelamine aremethoxymethylated, or mixtures thereof, and hexamethoxyethylmelamine,hexaacyloxymethylmelamine, a compound in which 1 to 6 methylol groups inhexamethylolmelamine are acyloxymethylated, or mixtures thereof.Specific examples of the epoxy compound include, but are not limited tothe following, tris(2,3-epoxypropyl)isocyanurate, trimethylolmethanetriglycidyl ether, trimethylolpropane triglycidyl ether, andtriethylolethane triglycidyl ether.

Specific examples of the guanamine compound include, but are not limitedto the following, tetramethylolguanamine, tetramethoxymethylguanamine, acompound in which 1 to 4 methylol groups in tetramethylolguanamine aremethoxymethylated, or mixtures thereof, and tetramethoxyethylguanamine,tetraacyloxyguanamine, a compound in which 1 to 4 methylol groups intetramethylolguanamine are acyloxymethylated, or mixtures thereof.Specific examples of the glycoluril compound include, but are notlimited to the following, tetramethylolglycoluril,tetramethoxyglycoluril, tetramethoxymethylglycoluril, a compound inwhich 1 to 4 methylol groups in tetramethylolglycoluril aremethoxymethylated, or mixtures thereof, and a compound in which 1 to 4methylol groups in tetramethylolglycoluril are acyloxymethylated, ormixtures thereof. Specific examples of the urea compound include, butare not limited to the following, tetramethylolurea,tetramethoxymethylurea, a compound in which 1 to 4 methylol groups intetramethylolurea are methoxymethylated, or mixtures thereof, andtetramethoxyethylurea.

Specific examples of the compound including an alkenyl ether groupinclude, but are not limited to the following, ethylene glycol divinylether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether,1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether,neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether,hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether,pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether,sorbitol tetravinyl ether, sorbitol pentavinyl ether, andtrimethylolpropane trivinyl ether.

In the composition for forming an underlayer film for lithography of thepresent embodiment, the content of the crosslinking agent is notparticularly limited, but the content is preferably 5 to 50 parts bymass, more preferably 10 to 40 parts by mass, based on 100 parts by massof the material for forming an underlayer film for lithography. Thecontent is set within the above preferable range to result in tendenciesto suppress the occurrence of the mixing phenomenon with the resistlayer, and to result in tendencies to enhance an antireflective effectand improve film formability after crosslinking.

[Acid Generating Agent]

The composition for forming an underlayer film for lithography of thepresent embodiment may also contain, if necessary, an acid generatingagent from the viewpoint of further promoting a crosslinking reaction byheat. As the acid generating agent, one for generating an acid bypyrolysis and one for generating an acid by light irradiation are known,and any of them can be used.

Examples of the acid generating agent include:

1) an onium salt of the following general formula (P1a-1), (P1a-2),(P1a-3) or (P1b),

2) a diazomethane derivative of the following general formula (P2),

3) a glyoxime derivative of the following general formula (P3),

4) a bissulfone derivative of the following general formula (P4),

5) a sulfonic acid ester of an N-hydroxyimide compound of the followinggeneral formula (P5),

6) a β-ketosulfonic acid derivative,

7) a disulfone derivative,

8) a nitrobenzylsulfonate derivative, and

9) a sulfonic acid ester derivative, but are not limited thereto.Herein, these acid generating agents can be used alone, or two or morethereof can be used in combination.

In the above formulae, each of R^(101a), R^(101b) and R^(101c)independently represents a linear, branched or cyclic alkyl group,alkenyl group, oxoalkyl group or oxoalkenyl group having 1 to 12 carbonatoms; an aryl group having 6 to 20 carbon atoms; or an aralkyl group oraryloxoalkyl group having 7 to 12 carbon atoms, and a part or all ofhydrogen atoms of these groups may be substituted with an alkoxy groupor the like. In addition, R^(101b) and R^(101c) may form a ring, and ifforming a ring, each of R^(101b) and R^(101c) independently representsan alkylene group having 1 to 6 carbon atoms. K⁻ represents anon-nucleophilic counter ion. R^(101d), R^(101e), R^(101f) and R^(101g)are represented by each independently adding a hydrogen atom toR^(101a), R^(101b) and R^(101c). R^(101d) and R^(101e), and R^(101d),R^(101e), and R^(101f) may form a ring, and if forming a ring, R^(101d)and R^(101e), and R^(101d), R^(101e) and R^(101f) represent an alkylenegroup having 3 to 10 carbon atoms, or a heteroaromatic ring havingtherein the nitrogen atom(s) in the formula.

R^(101a), R^(101b), R^(101c), R^(101d), R^(101e), R^(101f) and R^(101g)described above may be the same or different from one another.Specifically, examples of the alkyl group include, but are not limitedto the following, a methyl group, an ethyl group, a propyl group, anisopropyl group, a n-butyl group, a sec-butyl group, a tert-butyl group,a pentyl group, a hexyl group, a heptyl group, an octyl group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopropylmethyl group, a 4-methyl cyclohexyl group, a cyclohexylmethylgroup, a norbornyl group, and an adamantyl group. Examples of thealkenyl group include, but are not limited to the following, a vinylgroup, an allyl group, a propenyl group, a butenyl group, a hexenylgroup, and a cyclohexenyl group. Examples of the oxoalkyl group caninclude, but are not limited to the following, a 2-oxocyclopentyl group,a 2-oxocyclohexyl group, a 2-oxopropyl group, a 2-cyclopentyl-2-oxoethylgroup, a 2-cyclohexyl-2-oxoethyl group, and a2-(4-methylcyclohexyl)-2-oxoethyl group. Examples of the oxoalkenylgroup include, but are not limited to the following, a2-oxo-4-cyclohexenyl group and a 2-oxo-4-propenyl group. Examples of thearyl group include, but are not limited to the following, a phenylgroup, a naphthyl group, alkoxyphenyl groups such as a p-methoxyphenylgroup, a m-methoxyphenyl group, an o-methoxyphenyl group, anethoxyphenyl group, a p-tert-butoxyphenyl group, and am-tert-butoxyphenyl group; alkylphenyl groups such as a 2-methylphenylgroup, a 3-methylphenyl group, a 4-methylphenyl group, an ethylphenylgroup, a 4-tert-butylphenyl group, a 4-butylphenyl group, and adimethylphenyl group; alkylnaphthyl groups such as a methylnaphthylgroup and an ethylnaphthyl group; alkoxynaphthyl groups such as amethoxynaphthyl group and an ethoxynaphthyl group; dialkylnaphthylgroups such as a dimethylnaphthyl group and a diethylnaphthyl group; anddialkoxynaphthyl groups such as a dimethoxynaphthyl group and adiethoxynaphthyl group. Examples of the aralkyl group include, but arenot limited to the following, a benzyl group, a phenylethyl group, and aphenethyl group. Examples of the aryloxoalkyl group include, but are notlimited to the following, 2-aryl-2-oxoethyl groups such as a2-phenyl-2-oxoethyl group, a 2-(1-naphthyl)-2-oxoethyl group, and a2-(2-naphthyl)-2-oxoethyl group. Examples of the non-nucleophiliccounter ion, K⁻, include, but are not limited to the following, halideions such as a chloride ion and a bromide ion; fluoroalkyl sulfonatessuch as triflate, 1,1,1-trifluoroethane sulfonate, and nonafluorobutanesulfonate; aryl sulfonates such as tosylate, benzene sulfonate,4-fluorobenzene sulfonate, and 1,2,3,4,5-pentafluorobenzene sulfonate;and alkyl sulfonates such as mesylate and butane sulfonate.

In the case where R^(101d), R^(101e), R^(101f) and R^(101g) are each aheteroaromatic ring having the nitrogen atom(s) in the formula, examplesof the heteroaromatic ring include imidazole derivatives (for example,imidazole, 4-methylimidazole, and 4-methyl-2-phenylimidazole), pyrazolederivatives, furazan derivatives, pyrroline derivatives (for example,pyrroline and 2-methyl-1-pyrroline), pyrrolidine derivatives (forexample, pyrrolidine, N-methylpyrrolidine, pyrrolidinone, andN-methylpyrrolidone), imidazoline derivatives, imidazolidinederivatives, pyridine derivatives (for example, pyridine,methylpyridine, ethylpyridine, propylpyridine, butylpyridine,4-(1-butylpentyl)pyridine, dimethylpyridine, trimethylpyridine,triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine,4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine,butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone,4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine,2-(1-ethylpropyl)pyridine, aminopyridine, and dimethylaminopyridine),pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives,pyrazoline derivatives, pyrazolidine derivatives, piperidinederivatives, piperazine derivatives, morpholine derivatives, indolederivatives, isoindole derivatives, 1H-indazole derivatives, indolinederivatives, quinoline derivatives (for example, quinoline and3-quinolinecarbonitrile), isoquinoline derivatives, cinnolinederivatives, quinazoline derivatives, quinoxaline derivatives,phthalazine derivatives, purine derivatives, pteridin derivatives,carbazole derivatives, phenanthridine derivatives, acridine derivatives,phenazine derivatives, 1,10-phenanthroline derivatives, adeninederivatives, adenosine derivatives, guanine derivatives, guanosinederivatives, uracil derivative, and uridine derivatives.

The onium salts of the formula (P1a-1) and the formula (P1a-2) havefunctions as a photo acid generating agent and a thermal acid generatingagent. The onium salt of the formula (P1a-3) has a function as a thermalacid generating agent.

In the formula (P1b), each of R^(102a) and R^(102b) independentlyrepresents a linear, branched or cyclic alkyl group having 1 to 8 carbonatoms. R¹⁰³ represents a linear, branched or cyclic alkylene grouphaving 1 to 10 carbon atoms. Each of R^(104a) and R^(104b) independentlyrepresents a 2-oxoalkyl group having 3 to 7 carbon atoms. K⁻ representsa non-nucleophilic counter ion.

Specific examples of R^(102a) and R^(102b) include, but are not limitedto the following, a methyl group, an ethyl group, a propyl group, anisopropyl group, a n-butyl group, a sec-butyl group, a tert-butyl group,a pentyl group, a hexyl group, a heptyl group, an octyl group, acyclopentyl group, a cyclohexyl group, a cyclopropylmethyl group, a4-methyl cyclohexyl group, and a cyclohexylmethyl group. Specificexamples of R¹⁰³ include, but are not limited to the following, amethylene group, an ethylene group, a propylene group, a butylene group,a pentylene group, a hexylene group, a heptylene group, an octylenegroup, a nonylene group, a 1,4-cyclohexylene group, a 1,2-cyclohexylenegroup, a 1,3-cyclopentylene group, a 1,4-cyclooctylene group, and a1,4-cyclohexanedimethylene group. Specific examples of R^(104a) andR^(104b) include, but are not limited to the following, a 2-oxopropylgroup, a 2-oxocyclopentyl group, a 2-oxocyclohexyl group, and a2-oxocycloheptyl group. K⁻ includes the same as those described in theformula (P1a-1), (P1a-2) and (P1a-3).

In the formula (P2), each of R¹⁰⁵ and R¹⁰⁶ independently represents alinear, branched or cyclic alkyl group or halogenated alkyl group having1 to 12 carbon atoms, an aryl group or halogenated aryl group having 6to 20 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms.

Examples of the alkyl group in each of R¹⁰⁵ and R¹⁰⁶ include, but arenot limited to the following, a methyl group, an ethyl group, a propylgroup, an isopropyl group, a n-butyl group, a sec-butyl group, atert-butyl group, a pentyl group, a hexyl group, a heptyl group, anoctyl group, an amyl group, a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a norbornyl group, and an adamantyl group. Examplesof the halogenated alkyl group include, but are not limited to thefollowing, a trifluoromethyl group, a 1,1,1-trifluoroethyl group, a1,1,1-trichloroethyl group, and a nonafluorobutyl group. Examples of thearyl group include, but are not limited to the following, alkoxyphenylgroups such as a phenyl group, a p-methoxyphenyl group, am-methoxyphenyl group, an o-methoxyphenyl group, an ethoxyphenyl group,a p-tert-butoxyphenyl group, and a m-tert-butoxyphenyl group; andalkylphenyl groups such as a 2-methylphenyl group, a 3-methylphenylgroup, a 4-methylphenyl group, an ethylphenyl group, a4-tert-butylphenyl group, a 4-butylphenyl group, and a dimethylphenylgroup. Examples of the halogenated aryl group include, but are notlimited to the following, a fluorophenyl group, a chlorophenyl group,and a 1,2,3,4,5-pentafluorophenyl group. Examples of the aralkyl groupinclude, but are not limited to the following, a benzyl group and aphenethyl group.

In the formula (P3), each of R¹⁰⁷, R¹⁰⁸ and R¹⁰⁹ independentlyrepresents a linear, branched or cyclic alkyl group or halogenated alkylgroup having 1 to 12 carbon atoms; an aryl group or halogenated arylgroup having 6 to 20 carbon atoms; or an aralkyl group having 7 to 12carbon atoms. R¹⁰⁸ and R¹⁰⁹ may be bonded with each other to form acyclic structure, and if forming a cyclic structure, each of R¹⁰⁸ andR¹⁰⁹ represents a linear or branched alkylene group having 1 to 6 carbonatoms.

The alkyl group, halogenated alkyl group, aryl group, halogenated arylgroup, and aralkyl group in each of R¹⁰⁷, R¹⁰⁸ and R¹⁰⁹ include the sameas those described in R¹⁰⁵ and R¹⁰⁶. Herein, examples of the alkylenegroup in each of R¹⁰⁸ and R¹⁰⁹ include, but are not limited to thefollowing, a methylene group, an ethylene group, a propylene group, abutylene group, and a hexylene group.

In the formula (P4), R^(101a) and R^(101b) are the same as thosedescribed above.

In the formula (P5), R¹¹⁰ represents an arylene group having 6 to 10carbon atoms, an alkylene group having 1 to 6 carbon atoms, or analkenylene group having 2 to 6 carbon atoms, and a part or all ofhydrogen atoms of these groups may be further substituted with a linearor branched alkyl group or alkoxy group having 1 to 4 carbon atoms, anitro group, an acetyl group, or a phenyl group. R¹¹¹ represents alinear, branched or substituted alkyl group, alkenyl group oralkoxyalkyl group having 1 to 8 carbon atoms, a phenyl group, or anaphthyl group, and a part or all of hydrogen atoms of these groups maybe further substituted with an alkyl group or alkoxy group having 1 to 4carbon atoms; a phenyl group that may be substituted with an alkyl groupor alkoxy group having 1 to 4 carbon atoms, a nitro group, or an acetylgroup; a heteroaromatic group having 3 to 5 carbon atoms; or a chlorineatom or a fluorine atom.

Herein, examples of the arylene group in R¹¹⁰ include, but are notlimited to the following, a 1,2-phenylene group and a 1,8-naphthylenegroup. Examples of the alkylene group include, but are not limited tothe following, a methylene group, an ethylene group, a trimethylenegroup, a tetramethylene group, a phenylethylene group, and anorbornane-2,3-diyl group. Examples of the alkenylene group include, butare not limited to the following, a 1,2-vinylene group, a1-phenyl-1,2-vinylene group, and a 5-norbornene-2,3-diyl group. Thealkyl group in R¹¹¹ includes the same as those in R^(101a) to R^(101c).Examples of the alkenyl group include, but are not limited to thefollowing, a vinyl group, a 1-propenyl group, an allyl group, a1-butenyl group, a 3-butenyl group, an isoprenyl group, a 1-pentenylgroup, a 3-pentenyl group, a 4-pentenyl group, a dimethylallyl group, a1-hexenyl group, a 3-hexenyl group, a 5-hexenyl group, a 1-heptenylgroup, a 3-heptenyl group, a 6-heptenyl group, and a 7-octenyl group.Examples of the alkoxyalkyl group include, but are not limited to thefollowing, a methoxymethyl group, an ethoxymethyl group, a propoxymethylgroup, a butoxymethyl group, a pentyloxymethyl group, a hexyloxymethylgroup, a heptyloxymethyl group, a methoxyethyl group, an ethoxyethylgroup, a propoxyethyl group, a butoxyethyl group, a pentyloxyethylgroup, a hexyloxyethyl group, a methoxypropyl group, an ethoxypropylgroup, a propoxypropyl group, a butoxypropyl group, a methoxybutylgroup, an ethoxybutyl group, a propoxybutyl group, a methoxypentylgroup, an ethoxypentyl group, a methoxyhexyl group, and a methoxyheptylgroup.

Herein, Examples of the alkyl group having 1 to 4 carbon atoms, whichmay be further substituted, include, but are not limited to thefollowing, a methyl group, an ethyl group, a propyl group, an isopropylgroup, a n-butyl group, a an isobutyl group, and a tert-butyl group.Examples of the alkoxy group having 1 to 4 carbon atoms include, but arenot limited to the following, a methoxy group, an ethoxy group, apropoxy group, an isopropoxy group, a n-butoxy group, an isobutoxygroup, and tert-butoxy group. Examples of the phenyl group that may besubstituted with an alkyl group or alkoxy group having 1 to 4 carbonatoms, a nitro group, or an acetyl group include, but are not limited tothe following, a phenyl group, a tolyl group, a p-tert-butoxyphenylgroup, a p-acetylphenyl group, and a p-nitrophenyl group. Examples ofthe heteroaromatic group having 3 to 5 carbon atoms include, but are notlimited to the following, a pyridyl group and a furyl group.

Specific examples of the acid generating agent include, but are notlimited to the following, onium salts such as tetramethylammoniumtrifluoromethanesulfonate, tetramethylammoniumnonafluorobutanesulfonate, triethylammonium nonafluorobutanesulfonate,pyridinium nonafluorobutanesulfonate, triethylammonium camphorsulfonate,pyridinium camphorsulfonate, tetra n-butylammoniumnonafluorobutanesulfonate, tetraphenylammoniumnonafluorobutanesulfonate, tetramethylammonium p-toluenesulfonate,diphenyliodonium trifluoromethanesulfonate,(p-tert-butoxyphenyl)phenyliodonium trifluoromethanesulfonate,diphenyliodonium p-toluenesulfonate, (p-tert-butoxyphenyl)phenyliodoniump-toluenesulfonate, triphenylsulfonium trifluoromethanesulfonate,(p-tert-butoxyphenyl)diphenylsulfonium trifluoromethanesulfonate,bis(p-tert-butoxyphenyl)phenylsulfonium trifluoromethanesulfonate,tris(p-tert-butoxyphenyl)sulfonium trifluoromethanesulfonate,triphenylsulfonium p-toluenesulfonate,(p-tert-butoxyphenyl)diphenylsulfonium p-toluenesulfonate,bis(p-tert-butoxyphenyl)phenylsulfonium p-toluenesulfonate,tris(p-tert-butoxyphenyl)sulfonium p-toluenesulfonate,triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfoniumbutanesulfonate, trimethylsulfonium trifluoromethanesulfonate,trimethylsulfonium p-toluenesulfonate,cyclohexylmethyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate,cyclohexylmethyl(2-oxocyclohexyl)sulfonium p-toluenesulfonate,dimethylphenylsulfonium trifluoromethanesulfonate,dimethylphenylsulfonium p-toluenesulfonate, dicyclohexylphenylsulfoniumtrifluoromethanesulfonate, dicyclohexylphenylsulfoniump-toluenesulfonate, trinaphthylsulfonium trifluoromethanesulfonate,cyclohexylmethyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate,(2-norbornyl)methyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate,ethylene bis[methyl(2-oxocyclopentyl)sulfoniumtrifluoromethanesulfonate], and1,2′-naphthylcarbonylmethyltetrahydrothiophenium triflate; diazomethanederivatives such as bis(benzenesulfonyl)diazomethane,bis(p-toluenesulfonyl)diazomethane, bis(xylenesulfonyl)diazomethane,bis(cyclohexylsulfonyl)diazomethane,bis(cyclopentylsulfonyl)diazomethane, bis(n-butylsulfonyl)diazomethane,bis(isobutylsulfonyl)diazomethane, bis(sec-butylsulfonyl)diazomethane,bis(n-propylsulfonyl)diazomethane, bis(isopropylsulfonyl)diazomethane,bis(tert-butylsulfonyl)diazomethane, bis(n-amylsulfonyl)diazomethane,bis(isoamylsulfonyl)diazomethane, bis(sec-amylsulfonyl)diazomethane,bis(tert-amylsulfonyl)diazomethane,1-cyclohexylsulfonyl-1-(tert-butylsulfonyl)diazomethane,1-cyclohexylsulfonyl-1-(tert-amylsulfonyl)diazomethane, and1-tert-amylsulfonyl-1-(tert-butylsulfonyl)diazomethane; glyoximederivatives such as bis-(p-toluenesulfonyl)-α-dimethylglyoxime,bis-(p-toluesulfonyl)-α-diphenylglyoxime,bis-(p-toluenesulfonyl)-α-dicyclohexylglyoxime,bis-(p-toluenesulfonyl)-2,3-pentanedioneglyoxime,bis-(p-toluenesulfonyl)-2-methyl-3,4-pentanedioneglyoxime,bis-(n-butanesulfonyl)-α-dimethylglyoxime,bis-(n-butanesulfonyl)-α-diphenylglyoxime,bis-(n-butanesulfonyl)-α-dicyclohexylglyoxime,bis-(n-butanesulfonyl)-2,3-pentanedioneglyoxime,bis-(n-butanesulfonyl)-2-methyl-3,4-pentanedioneglyoxime,bis-(methanesulfonyl)-α-dimethylglyoxime,bis-(trifluoromethanesulfonyl)-α-dimethylglyoxime,bis-(1,1,1-trifluoroethanesulfonyl)-α-dimethylglyoxime,bis-(tert-butanesulfonyl)-α-dimethylglyoxime,bis-(perfluorooctanesulfonyl)-α-dimethylglyoxime,bis-(cyclohexanesulfonyl)-α-dimethylglyoxime,bis-(benzenesulfonyl)-α-dimethylglyoxime,bis-(p-fluorobenzenesulfonyl)-α-dimethylglyoxime,bis-(p-tert-butylbenzenesulfonyl)-α-dimethylglyoxime,bis-(xylenesulfonyl)-α-dimethylglyoxime, andbis-(camphorsulfonyl)-α-dimethylglyoxime; bissulfone derivatives, suchas bisnaphthylsulfonylmethane, bistrifluoromethylsulfonylmethane,bismethylsulfonylmethane, bisethylsulfonylmethane,bispropylsulfonylmethane, bisisopropylsulfonylmethane,bis-p-toluenesulfonylmethane, and bisbenzenesulfonylmethane;β-ketosulfone derivatives such as2-cyclohexylcarbonyl-2-(p-toluenesulfonyl)propane and2-isopropylcarbonyl-2-(p-toluenesulfonyl)propane; disulfone derivativessuch as a diphenyldisulfone derivative and a dicyclohexyldisulfonederivative, nitrobenzylsulfonate derivatives such as 2,6-dinitrobenzylp-toluenesulfonate and 2,4-dinitrobenzyl p-toluenesulfonate; sulfonicacid ester derivatives such as 1,2,3-tris(methanesulfonyloxy)benzene,1,2,3-tris(trifluoromethanesulfonyloxy)benzene, and1,2,3-tris(p-toluenesulfonyloxy)benzene; and sulfonic acid esterderivatives of a N-hydroxyimide compound, such as N-hydroxysuccinimidemethanesulfonic acid ester, N-hydroxysuccinimidetrifluoromethanesulfonic acid ester, N-hydroxysuccinimide ethanesulfonicacid ester, N-hydroxysuccinimide 1-propanesulfonic acid ester,N-hydroxysuccinimide 2-propanesulfonic acid ester, N-hydroxysuccinimide1-pentanesulfonic acid ester, N-hydroxysuccinimide 1-octanesulfonic acidester, N-hydroxysuccinimide p-toluenesulfonic acid ester,N-hydroxysuccinimide p-methoxybenzenesulfonic acid ester,N-hydroxysuccinimide 2-chloroethanesulfonic acid ester,N-hydroxysuccinimide benzenesulfonic acid ester,N-hydroxysuccinimide-2,4,6-trimethylbenzenesulfonic acid ester,N-hydroxysuccinimide 1-naphthalenesulfonic acid ester,N-hydroxysuccinimide 2-naphthalenesulfonic acid ester,N-hydroxy-2-phenylsuccinimide methanesulfonic acid ester,N-hydroxymaleimide methanesulfonic acid ester, N-hydroxymaleimideethanesulfonic acid ester, N-hydroxy-2-phenylmaleimide methanesulfonicacid ester, N-hydroxyglutarimide methanesulfonic acid ester,N-hydroxyglutarimide benzenesulfonic acid ester, N-hydroxyphthalimidemethanesulfonic acid ester, N-hydroxyphthalimide benzenesulfonic acidester, N-hydroxyphthalimide trifluoromethanesulfonic acid ester,N-hydroxyphthalimide p-toluenesulfonic acid ester,N-hydroxynaphthalimide methanesulfonic acid ester,N-hydroxynaphthalimide benzenesulfonic acid ester,N-hydroxy-5-norbornene-2,3-dicarboxyimide methanesulfonic acid ester,N-hydroxy-5-norbornene-2,3-dicarboxyimide trifluoromethanesulfonic acidester, and N-hydroxy-5-norbornene-2,3-dicarboxyimide p-toluenesulfonicacid ester.

Among them, in particular, onium salts such as triphenylsulfoniumtrifluoromethanesulfonate, (p-tert-butoxyphenyl)diphenylsulfoniumtrifluoromethanesulfonate, tris(p-tert-butoxyphenyl)sulfoniumtrifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate,(p-tert-butoxyphenyl)diphenylsulfonium p-toluenesulfonate,tris(p-tert-butoxyphenyl)sulfonium p-toluenesulfonate,trinaphthylsulfonium trifluoromethanesulfonate,cyclohexylmethyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate,(2-norbornyl)methyl(2-oxocyclohexyl)sulfonium trifluoromethanesulfonate,and 1,2′-naphthylcarbonylmethyltetrahydrothiophenium triflate;diazomethane derivatives such as bis(benzenesulfonyl)diazomethane,bis(p-toluenesulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane,bis(n-butylsulfonyl)diazomethane, bis(isobutylsulfonyl)diazomethane,bis(sec-butylsulfonyl)diazomethane, bis(n-propylsulfonyl)diazomethane,bis(isopropylsulfonyl)diazomethane, andbis(tert-butylsulfonyl)diazomethane; glyoxime derivatives such asbis-(p-toluenesulfonyl)-α-dimethylglyoxime andbis-(n-butanesulfonyl)-α-dimethylglyoxime, bissulfone derivatives suchas bisnaphthylsulfonylmethane; and sulfonic acid ester derivatives of anN-hydroxyimide compound, such as N-hydroxysuccinimide methanesulfonicacid ester, N-hydroxysuccinimide trifluoromethanesulfonic acid ester,N-hydroxysuccinimide 1-propanesulfonic acid ester, N-hydroxysuccinimide2-propanesulfonic acid ester, N-hydroxysuccinimide 1-pentanesulfonicacid ester, N-hydroxysuccinimide p-toluenesulfonic acid ester,N-hydroxynaphthalimide methanesulfonic acid ester, andN-hydroxynaphthalimide benzenesulfonic acid ester, and the like arepreferably used.

In the composition for forming an underlayer film for lithographyaccording to the present embodiment, the content of the acid generatingagent is not particularly limited, but the content is preferably 0.1 to50 parts by mass and more preferably 0.5 to 40 parts by mass, based on100 parts by mass of the material for forming an underlayer film forlithography. The content is set within the above range to result in atendency to increase the acid generation amount to promote acrosslinking reaction, and also to result in a tendency to suppress theoccurrence of the mixing phenomenon with a resist layer.

[Basic Compound]

Furthermore, the composition for forming an underlayer film forlithography of the present embodiment may contain a basic compound fromthe viewpoint of improving preservation stability.

The basic compound serves as a quencher to an acid for preventing atrace amount of the acid generated from the acid generating agent frompromoting a crosslinking reaction. Examples of such a basic compoundinclude primary, secondary, and tertiary aliphatic amines, mixed amines,aromatic amines, heterocyclic amines, a nitrogen-containing compoundhaving a carboxy group, a nitrogen-containing compound having a sulfonylgroup, a nitrogen-containing compound having a hydroxyl group, anitrogen-containing compound having a hydroxyphenyl group, an alcoholicnitrogen-containing compound, an amide derivative, and an imidederivative, but are not limited thereto.

Specifically, specific examples of the primary aliphatic amines include,but are not limited to the following, ammonia, methylamine, ethylamine,n-propylamine, isopropylamine, n-butylamine, isobutylamine,sec-butylamine, tert-butylamine, pentylamine, tert-amylamine,cyclopentylamine, hexylamine, cyclohexylamine, heptylamine, octylamine,nonylamine, decylamine, dodecylamine, cetylamine, methylenediamine,ethylenediamine, and tetraethylenepentamine. Specific examples of thesecondary aliphatic amines include, but are not limited to thefollowing, dimethylamine, diethylamine, di-n-propylamine,diisopropylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine,dipentylamine, dicyclopentylamine, dihexylamine, dicyclohexylamine,diheptylamine, dioctylamine, dinonylamine, didecylamine, didodecylamine,dicetylamine, N,N-dimethylmethylenediamine, N,N-dimethylethylenediamine,and N,N-dimethyltetraethylenepentamine. Specific examples of thetertiary aliphatic amines include, but are not limited to the following,trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine,tri-n-butylamine, triisobutylamine, tri-sec-butylamine, tripentylamine,tricyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine,trioctylamine, trinonylamine, tridecylamine, tridodecylamine,tricetylamine, N,N,N′,N′-tetramethylmethylenediamine,N,N,N′,N′-tetramethylethylenediamine, andN,N,N′,N′-tetramethyltetraethylenepentamine.

Specific examples of the mixed amines include, but are not limited tothe following, dimethylethylamine, methylethylpropylamine, benzylamine,phenethylamine, and benzyldimethylamine. Specific examples of thearomatic amines and heterocyclic amines include, but are not limited tothe following, aniline derivatives (for example, aniline,N-methylaniline, N-ethylaniline, N-propylaniline, N,N-dimethylaniline,2-methylaniline, 3-methylaniline, 4-methylaniline, ethylaniline,propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline,4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline,3,5-dinitroaniline, and N,N-dimethyltoluidine), diphenyl(p-tolyl)amine,methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine,diaminonaphthalene, pyrrole derivatives (for example, pyrrole,2H-pyrrole, 1-methylpyrrole, 2,4-dimethylpyrrole, 2,5-dimethylpyrrole,and N-methylpyrrole), oxazole derivatives (for example, oxazole andisoxazole), thiazole derivatives (for example, thiazole andisothiazole), imidazole derivatives (for example, imidazole,4-methylimidazole, and 4-methyl-2-phenylimidazole), pyrazolederivatives, furazan derivatives, pyrroline derivatives (for example,pyrroline and 2-methyl-1-pyrroline), pyrrolidine derivatives (forexample, pyrrolidine, N-methylpyrrolidine, pyrrolidinone, andN-methylpyrrolidone), imidazoline derivatives, imidazolidinederivatives, pyridine derivatives (for example, pyridine,methylpyridine, ethylpyridine, propylpyridine, butylpyridine,4-(1-butylpentyl)pyridine, dimethylpyridine, trimethylpyridine,triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine,4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine,butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone,4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine,2-(1-ethylpropyl)pyridine, aminopyridine, and dimethylaminopyridine),pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives,pyrazoline derivatives, pyrazolidine derivatives, piperidinederivatives, piperazine derivatives, morpholine derivatives, indolederivatives, isoindole derivatives, 1H-indazole derivatives, indolinederivatives, quinoline derivatives (for example, quinoline,3-quinolinecarbonitrile), isoquinoline derivatives, cinnolinederivatives, quinazoline derivatives, quinoxaline derivatives,phthalazine derivatives, purine derivatives, pteridin derivatives,carbazole derivatives, phenanthridine derivatives, acridine derivatives,phenazine derivatives, 1,10-phenanthroline derivatives, adeninederivatives, adenosine derivatives, guanine derivatives, guanosinederivatives, uracil derivatives, and uridine derivatives.

Furthermore, specific examples of the nitrogen-containing compoundhaving a carboxy group include, but are not limited to the following,aminobenzoic acid, indolecarboxylic acid, and amino acid derivatives(for example, nicotinic acid, alanine, arginine, aspartic acid, glutamicacid, glycine, histidine, isoleucine, glycylleucine, leucine,methionine, phenylalanine, threonine, lysine,3-aminopyrazine-2-carboxylic acid, and methoxyalanine). Specificexamples of the nitrogen-containing compound having a sulfonyl groupinclude, but are not limited to the following, 3-pyridinesulfonic acidand pyridinium p-toluenesulfonate. Specific examples of thenitrogen-containing compound having a hydroxyl group, thenitrogen-containing compound having a hydroxyphenyl group, and thealcoholic nitrogen-containing compound include, but are not limited tothe following, 2-hydroxypyridine, aminocresol, 2,4-quinolinediol,3-indolemethanol hydrate, monoethanolamine, diethanolamine,triethanolamine, N-ethyldiethanolamine, N,N-diethylethanolamine,triisopropanolamine, 2,2′-iminodiethanol, 2-aminoethanol,3-amino-1-propanol, 4-amino-1-butanol, 4-(2-hydroxyethyl)morpholine,2-(2-hydroxyethyl)pyridine, 1-(2-hydroxyethyl)piperazine,1-[2-(2-hydroxyethoxy)ethyl]piperazine, piperidine ethanol,1-(2-hydroxyethyl)pyrrolidine, 1-(2-hydroxyethyl)-2-pyrrolidone,3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol,8-hydroxyjulolidine, 3-quinuclidinol, 3-tropanol, 1-methyl-2-pyrrolidineethanol, 1-aziridine ethanol, N-(2-hydroxyethyl)phthalimide, andN-(2-hydroxyethyl)isonicotinamide. Specific examples of the amidederivative include, but are not limited to the following, formamide,N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide,N,N-dimethylacetamide, propionamide, and benzamide. Specific examples ofthe imide derivative include, but are not limited to the following,phthalimide, succinimide, and maleimide.

In the composition for forming an underlayer film for lithographyaccording to the present embodiment, the content of the basic compoundis not particularly limited, but the content is preferably 0.001 to 2parts by mass and more preferably 0.01 to 1 part by mass, based on 100parts by mass of the material for forming an underlayer film forlithography. The content is set within the above preferable range toresult in a tendency to improve preservation stability withoutexcessively interrupting a crosslinking reaction.

In addition, the composition for forming an underlayer film forlithography of the present embodiment may contain other resins and/orcompounds for the purpose of imparting heat curability and controllingabsorbance. Such other resins and/or compounds include naphthol resins,xylene resins, naphthol-modified resins, phenol-modified resins ofnaphthalene resins, polyhydroxystyrene, dicyclopentadiene resins,(meth)acrylate, dimethacrylate, trimethacrylate, tetramethacrylate,resins having a naphthalene ring such as vinylnaphthalene andpolyacenaphthylene, resins having a biphenyl ring such asphenanthrenequinone and fluorene, resins having a heterocyclic ringhaving a hetero atom such as thiophene and indene, and resins notcontaining an aromatic ring; rosin-based resins, and resins or compoundsincluding an alicyclic structure, such as cyclodextrin,adamantane(poly)ol, tricyclodecane(poly)ol and derivatives thereof, butare not limited thereto. Furthermore, the composition for forming anunderlayer film for lithography of the present embodiment can alsocontain a known additive. Examples of the known additive includes, butnot limited to the following, an ultraviolet absorber, a surfactant, acolorant and a non-ionic surfactant.

[Underlayer Film for Lithography and Multilayer Resist Pattern FormingMethod]

An underlayer film for lithography of the present embodiment is formedfrom the composition for forming an underlayer film for lithography ofthe present embodiment.

In addition, a resist pattern forming method of the present embodimentincludes step (A-1) of forming an underlayer film on a substrate byusing the composition for forming an underlayer film for lithography ofthe present embodiment, step (A-2) of forming at least one photoresistlayer on the underlayer film, and step (A-3) of, after the secondforming step, irradiating a predetermined region of the photoresistlayer with radiation, followed by developing.

Furthermore, a circuit pattern forming method of the present embodimentincludes step (B-1) of forming an underlayer film on a substrate byusing the composition for forming an underlayer film for lithography ofthe present embodiment, step (B-2) of forming an intermediate layer filmon the underlayer film by using a silicon atom-containing resistintermediate layer film material, step (B-3) of forming at least onephotoresist layer on the intermediate layer film, step (B-4) of, afterstep (B-3), irradiating a predetermined region of the photoresist layerwith radiation, followed by developing to form a resist pattern, andstep (B-5) of, after step (B-4), etching the intermediate layer filmwith the resist pattern as a mask, etching the underlayer film with theobtained intermediate layer film pattern as an etching mask and etchingthe substrate with the obtained underlayer film pattern as an etchingmask, to form a pattern on the substrate.

The underlayer film for lithography of the present embodiment is notparticularly limited in terms of the forming method thereof as long asit is formed from the composition for forming an underlayer film forlithography of the present embodiment, and a known method can beapplied. For example, the underlayer film can be formed by applying thecomposition for forming an underlayer film for lithography of thepresent embodiment on the substrate by a known coating method orprinting method such as spin coating or screen printing, and removing anorganic solvent by volatilization or the like.

The underlayer film is preferably baked upon forming in order tosuppress the occurrence of the mixing phenomenon with an upperlayerresist and also promote a crosslinking reaction. In this case, thebaking temperature is not particularly limited, but it is preferablywithin the range of 80 to 450° C., and more preferably 200 to 400° C. Inaddition, the baking time is not also particularly limited, but ispreferably within the range of 10 to 300 seconds. Herein, the thicknessof the underlayer film can be appropriately selected depending on therequired properties, and is not particularly limited, but the thicknessis usually preferably about 30 to 20,000 nm and more preferably 50 to15,000 nm.

After the underlayer film is prepared, in the case of a two-layerprocess, a silicon-containing resist layer or a usual single-layerresist including a hydrocarbon is preferably prepared on the underlayerfilm, and in the case of a three-layer process, a silicon-containingintermediate layer is preferably prepared on the underlayer film, and asingle-layer resist layer not containing silicon is preferably preparedon the silicon-containing intermediate layer. In these cases, knownphotoresist materials for forming the resist layer can be used.

After the underlayer film is prepared on the substrate, in the case of atwo-layer process, a silicon-containing resist layer or a usualsingle-layer resist including a hydrocarbon can be prepared on theunderlayer film. In the case of a three-layer process, asilicon-containing intermediate layer can be prepared on the underlayerfilm, and a single-layer resist layer not containing silicon can beprepared on the silicon-containing intermediate layer. In these cases, aphotoresist material for forming the resist layer, which can be used, isappropriately selected from known ones, and is not particularly limited.

As the silicon-containing resist material for a two-layer process, apositive-type photoresist material, which contains a siliconatom-containing polymer such as a polysilsesquioxane derivative or avinylsilane derivative, is preferably used as a base polymer from theviewpoint of oxygen gas-etching resistance. Also, an organic solvent, anacid generating agent and if necessary a basic compound can preferablyused. Herein, as the silicon atom-containing polymer, a known polymerused in such a resist material can be used.

As the silicon-containing intermediate layer for a three-layer process,a polysilsesquioxane-based intermediate layer is preferably used. Theintermediate layer is allowed to have an effect as an antireflectivefilm, and thus tends to make it possible to effectively suppressreflection. For example, if a material including many aromatic groupsand having a high substrate-etching resistance is used for theunderlayer film in a 193 nm exposure process, a k-value tends to beincreased to increase substrate reflection, but the reflection can besuppressed by the intermediate layer to thereby make the substratereflection 0.5% or less. For the intermediate layer having such anantireflection effect, but not limited to the following,polysilsesquioxane into which a phenyl group or a light-absorbing grouphaving a silicon-silicon bond for 193 nm exposure is introduced andwhich is to be crosslinked with an acid or heat is preferably used.

An intermediate layer formed by the Chemical Vapour Deposition (CVD)method can also be used. As the intermediate layer having a high effectas an antireflective film, prepared by the CVD method, but not limitedto the following, for example, a SiON film is known. In general, theintermediate layer is formed by a wet process such as a spin coatingmethod or screen printing rather than the CVD method in terms ofsimplicity and cost effectiveness. Herein, the upperlayer resist in athree-layer process may be of positive-type or negative-type, and thesame one as a commonly used single-layer resist can be used therefor.

Furthermore, the underlayer film of the present embodiment can also beused as a usual antireflective film for use in a single-layer resist ora usual underlying material for suppressing pattern collapse. Theunderlayer film of the present embodiment can also be expected to serveas a hard mask for underlying processing because of being excellent inetching resistance for underlying processing.

In the case where a resist layer is formed by the photoresist material,a wet process such as a spin coating method or screen printing ispreferably used as in the case of forming the underlayer film. Theresist material is coated by a spin coating method or the like and thenusually pre-baked, and such pre-baking is preferably performed in therange of 80 to 180° C. for 10 to 300 seconds. Thereafter, in accordancewith an ordinary method, the resultant can be subjected to exposure,post-exposure bake (PEB), and development to obtain a resist pattern.Herein, the thickness of the resist film is not particularly limited,but generally, it is preferably 30 to 500 nm and more preferably 50 to400 nm.

Light for use in exposure may be appropriately selected depending on thephotoresist material to be used. In general, examples thereof includehigh energy radiation having a wavelength of 300 nm or less,specifically, excimer lasers of 248 nm, 193 nm, and 157 nm, a soft X-rayof 3 to 20 nm, electron beam, and an X-ray.

The resist pattern formed by the above method is a pattern whosecollapse is suppressed by the underlayer film of the present embodiment.Therefore, the underlayer film of the present embodiment can be used tothereby obtain a finer pattern, and an exposure amount necessary forobtaining such a resist pattern can be reduced.

Then, the obtained resist pattern is used as a mask to perform etching.As the etching of the underlayer film in a two-layer process, gasetching is preferably used. As the gas etching, etching using oxygen gasis suitable. In addition to oxygen gas, an inert gas such as He and Ar,and CO, CO₂, NH₃, SO₂, N₂, NO₂, and H₂ gases can also be added. The gasetching can also be performed not using oxygen gas but using only CO,CO₂, NH₃, N₂, NO₂, and H₂ gases. In particular, the latter gases arepreferably used for protecting a side wall for preventing a pattern sidewall from being undercut.

On the other hand, also in the etching of the intermediate layer in athree-layer process, gas etching is preferably used. As the gas etching,the same one as the one described in a two-layer process can be applied.In particular, the intermediate layer is preferably processed in athree-layer process using a fluorocarbon gas with the resist pattern asa mask. Thereafter, as described above, the intermediate layer patternis used as a mask to perform, for example, oxygen gas etching, therebyprocessing the underlayer film.

Herein, in the case where an inorganic hard mask intermediate layer filmis formed as the intermediate layer, a silicon oxide film, a siliconnitride film, and a silicon oxynitride film (SiON film) are formed bythe CVD method, the ALD method, and the like. The nitride film formingmethod that can be used is, but not limited to the following, any methoddescribed in, for example, Japanese Patent Laid-Open No. 2002-334869(Patent Literature 6) and WO2004/066377 (Patent Literature 7). While thephotoresist film can be directly formed on such an intermediate layerfilm, an organic antireflective film (BARC) may also be formed on theintermediate layer film by spin coating, and the photoresist film mayalso be formed thereon.

As the intermediate layer, a polysilsesquioxane-based intermediate layeris also preferably used. The resist intermediate layer film is allowedto have an effect as an antireflective film, and thus tends to make itpossible to effectively suppress reflection. A specific material for thepolysilsesquioxane-based intermediate layer that can be used is, but notlimited to the following, any material described in, for example,Japanese Patent Laid-Open No. 2007-226170 (Patent Literature 8) andJapanese Patent Laid-Open No. 2007-226204 (Patent Literature 9).

The next etching of the substrate can also be performed by an ordinarymethod, and, for example, when the substrate is made of SiO₂ or SiN,etching with mainly a fluorocarbon gas can be performed, and when thesubstrate is made of p-Si, Al, or W, etching mainly using achlorine-based gas or bromine-based gas can be performed. In the casewhere the substrate is processed by the etching with a fluorocarbon gas,the silicon-containing resist in a two-layer resist process and thesilicon-containing intermediate layer in a three-layer process arepeeled off at the same time as the processing of the substrate. On theother hand, in the case where the substrate is processed by the etchingwith a chlorine-based gas or bromine-based gas, the silicon-containingresist layer or the silicon-containing intermediate layer is peeled offseparately, and is generally peeled off by dry etching with afluorocarbon gas after the substrate is processed.

The underlayer film of the present embodiment is characterized by beingexcellent in etching resistance of such a substrate. Herein, thesubstrate that can be used is appropriately selected from known ones,and is not particularly limited, but includes Si, α-Si, p-Si, SiO₂, SiN,SiON, W, TiN, and Al substrates. In addition, the substrate may also bea laminate having a processed film (processed substrate) on a basematerial (support). Such a processed film includes various Low-k filmsmade of Si, SiO₂, SiON, SiN, p-Si, α-Si, W, W—Si, Al, Cu, and Al—Si, andstopper films thereof, and a material different from the base material(support) is usually used therefor. Herein, the thickness of thesubstrate to be processed or the processed film is not particularlylimited, but it is usually preferably about 50 to 10,000 nm and morepreferably 75 to 5,000 nm.

[Method for Purifying Compound or Resin]

A method for purifying the compound or the resin of the presentembodiment includes a step of bringing a solution including an organicsolvent optionally immiscible with water and the compound or the resininto contact with an acidic aqueous solution for extraction. Morespecifically, in the present embodiment, the compound represented by theformula (1) or the resin obtained by using the compound as a monomer canbe purified by dissolving the compound or the resin in an organicsolvent optionally immiscible with water, bringing the solution intocontact with an acidic aqueous solution for performing an extractiontreatment, to thereby transfer a metal content included in the solution(A) including the compound or the resin and the organic solvent to anaqueous phase, and then separating an organic phase and the aqueousphase. The purification method of the present embodiment can allow thecontents of various metals in the compound represented by the formula(1) or the resin obtained by using the compound as a monomer to beremarkably reduced.

In the present embodiment, the organic solvent optionally immisciblewith water means an organic solvent whose solubility in water at roomtemperature is less than 30%. Herein, the solubility is preferably lessthan 20%, more preferably less than 10%. The organic solvent optionallyimmiscible with water is not particularly limited, but it is preferablyan organic solvent that can be safely applied to a semiconductormanufacturing process. The amount of the organic solvent to be used isusually about 1 to 100 times the amount of the compound represented bythe formula (1) or the resin obtained by using the compound as amonomer, to be used.

Specific examples of the solvent to be used include, but not limited tothe following, ethers such as diethyl ether and diisopropyl ether,esters such as ethyl acetate, butyl acetate and isoamyl acetate, ketonessuch as methyl ethyl ketone, 1,2-diethoxyketone, methyl isobutyl ketone,ethyl isobutyl ketone, cyclohexanone, cyclopentanone, 2-heptanone and2-pentanone, glycol ether acetates such as ethylene glycol monoethylether acetate, ethylene glycol monobutyl ether acetate, propylene glycolmonomethyl ether acetate (PGMEA) and propylene glycol monoethyl etheracetate, aliphatic hydrocarbons such as n-hexane and n-heptane, aromatichydrocarbons such as toluene and xylene, and halogenated hydrocarbonssuch as methylene chloride and chloroform. Among them, toluene,2-heptanone, cyclohexanone, cyclopentanone, methyl isobutyl ketone,propylene glycol monomethyl ether acetate, 1,2-diethoxyketone, butylacetate, ethyl acetate, and the like are preferable, and cyclohexanoneand propylene glycol monomethyl ether acetate are more preferable. Thesesolvents can be used singly or as a mixture of two or more thereof.

The acidic aqueous solution to be used in the present embodiment isappropriately selected from aqueous solutions in which an organic orinorganic compound commonly known is dissolved in water. Examplesinclude an aqueous solution in which a mineral acid such as hydrochloricacid, sulfuric acid, nitric acid or phosphoric acid is dissolved inwater, or an aqueous solution in which an organic acid such as aceticacid, propionic acid, oxalic acid, malonic acid, succinic acid, fumaricacid, maleic acid, tartaric acid, citric acid, methanesulfonic acid,phenolsulfonic acid, p-toluenesulfonic acid or trifluoroacetic acid isdissolved in water. These acidic aqueous solutions can be used singly orin combinations of two or more thereof. Among these acidic aqueoussolutions, an aqueous solution of sulfuric acid, nitric acid, or acarboxylic acid such as acetic acid, oxalic acid, tartaric acid orcitric acid is preferable, an aqueous solution of sulfuric acid, oxalicacid, tartaric acid or citric acid is more preferable, and an aqueoussolution of oxalic acid is further preferable. It is considered that apolyvalent carboxylic acid such as oxalic acid, tartaric acid and citricacid is coordinated with a metal ion to exert a chelating effect, andtherefore tends to allow a metal to be more effectively removed. Inaddition, the water to be here used is preferably water having a lowmetal content according to the purpose of the present embodiment, suchas ion-exchange water.

The pH of the acidic aqueous solution to be used in the presentembodiment is not particularly limited, but the acidity of the aqueoussolution is preferably adjusted in consideration of the effect on thecompound represented by the formula (1) or the resin obtained by usingthe compound as a monomer. The pH is usually in the range from about 0to 5, more preferably about 0 to 3.

The amount of the acidic aqueous solution to be used in the presentembodiment is not particularly limited, but the amount to be used ispreferably adjusted from the viewpoint of reducing the number ofextractions for metal removal and the viewpoint of ensuring operationproperty in consideration of the total amount of the liquid. The amountof the aqueous solution to be used is usually 10 to 200% by mass,preferably 20 to 100% by mass, relative to the solution of the compoundrepresented by the formula (1) or the resin obtained by using thecompound as a monomer, dissolved in the organic solvent.

In the present embodiment, the acidic aqueous solution is brought intocontact with the solution (A) including the compound represented by theformula (1) or the resin obtained by using the compound as a monomer andthe organic solvent optionally immiscible with water, to thereby extractthe metal content.

The temperature in performing of the extraction treatment is usually inthe range from 20 to 90° C., preferably 30 to 80° C. The extractionoperation is performed by, for example, well mixing with stirring or thelike and thereafter standing. Thus, the metal content included in thesolution including the compound represented by the formula (1) or theresin obtained by using the compound as a monomer and the organicsolvent is transferred to the aqueous phase. In addition, the operationcan allow the acidity of the solution to be reduced, suppressing thechange of properties of the compound represented by the formula (1) orthe resin obtained by using the compound as a monomer.

The resulting mixture is separated to the solution phase including thecompound represented by the formula (1) or the resin obtained by usingthe compound as a monomer and the organic solvent, and the aqueousphase, and therefore the solution including the compound represented bythe formula (1) or the resin obtained by using the compound as a monomerand the organic solvent is recovered by decantation or the like. Thestanding time is not particularly limited, but the standing time ispreferably adjusted from the viewpoint of providing better separation tothe solution phase including the organic solvent, and the aqueous phase.The standing time is usually 1 minute or more, preferably 10 minutes ormore, more preferably 30 minutes or more. In addition, the extractiontreatment may be performed only once, but is also effectively performedwith operations such as mixing, standing and separation being repeatedlyperformed multiple times.

In the present embodiment, a step of performing an extraction treatmentwith water is preferably further included after the step of bringing thesolution (A) into contact with the acidic aqueous solution forextraction. That is, preferably, the extraction treatment is performedby using the acidic aqueous solution, thereafter the solution (A)including the compound represented by the formula (1) or the resinobtained by using the compound as a monomer, extracted and recoveredfrom the aqueous solution, and the organic solvent, is preferablyfurther subjected to the extraction treatment with water. The extractionoperation with water is performed by, for example, well mixing withstirring or the like and thereafter standing. The resulting solution isseparated to the solution phase including the compound represented bythe formula (1) or the resin obtained by using the compound as a monomerand the organic solvent, and the aqueous phase, and therefore thesolution phase including the compound represented by the formula (1) orthe resin obtained by using the compound as a monomer and the organicsolvent is recovered by decantation or the like. In addition, the waterto be here used is preferably water having a low metal content accordingto the purpose of the present embodiment, such as ion-exchange water.The extraction treatment may be performed only once, but is alsoeffectively performed with operations such as mixing, standing andseparation being repeatedly performed multiple times. In addition,conditions in the extraction treatment, such as the ratio of both to beused, the temperature and the time, are not particularly limited, butmay be the same as in the case of the contact treatment with the acidicaqueous solution above.

The water content that can be incorporated in the solution thusobtained, including the compound represented by the formula (1) or theresin obtained by using the compound as a monomer and the organicsolvent, can be easily removed by performing an operation such asdistillation under reduced pressure. In addition, an organic solvent canbe if necessary added to adjust the concentration of the compoundrepresented by the formula (1) or the resin obtained by using thecompound as a monomer to any concentration.

The method of isolating the compound represented by the formula (1) orthe resin obtained by using the compound as a monomer from the resultingsolution including the compound represented by the formula (1) or theresin obtained by using the compound as a monomer and the organicsolvent can be performed by a known method such as removal under reducedpressure, separation by reprecipitation and a combination thereof. Ifnecessary, a known treatment such as a concentration operation, afiltration operation, a centrifugation operation and a drying operationcan be performed.

EXAMPLES

Hereinafter, the present embodiment will be described by Examples andComparative Examples in more detail, but the present embodiment is notlimited thereto at all.

(Carbon Concentration and Oxygen Concentration)

The carbon concentration and the oxygen concentration (% by mass) weremeasured by organic element analysis.

Apparatus: CHN CORDER MT-6 (manufactured by Yanaco Bunseki Kogyo Co.)

(Molecular Weight)

Measurement was performed by LC-MS analysis using AcquityUPLC/MALDI-Synapt HDMS manufactured by Water.

(Molecular Weight in Terms of Polystyrene)

Gel permeation chromatography (GPC) analysis was used to determine theweight average molecular weight (Mw) and the number average molecularweight (Mn) in terms of polystyrene, and to determine the degree ofdispersion (Mw/Mn).

Apparatus: Shodex GPC-101 type (manufactured by Showa Denko K. K.)

Column: KF-80M×3

Eluent: THF 1 mL/min

Temperature: 40° C.

(Pyrolysis Temperature (Tg))

An EXSTAR 6000 DSC apparatus manufactured by SII NanoTechnology Inc. wasused, and about 5 mg of a sample was placed in an unsealed aluminumcontainer and heated to 500° C. at a rate of temperature rise of 10°C./min in a nitrogen gas (30 mL/min) stream. In this time, a temperatureat which a reducing portion appeared on the base line was defined as apyrolysis temperature (Tg).

(Solubility)

The amount of each compound dissolved in 1-methoxy-2-propanol (PGME) andpropylene glycol monomethyl ether acetate (PGMEA) was measured at 23°C., and the results were evaluated according to the following criteria.

Evaluation A: 10% by weight or more

Evaluation B: 5% by weight or more and less than 10% by weight

Evaluation C: less than 5% by weight

(Synthesis Example 1) Synthesis of CAX-1

A container having an inner volume of 200 mL, equipped with a stirrer, acondenser and a burette, was prepared. To this container were charged17.8 g (80 mmol) of N-ethylcarbazole-3-carbaldehyde (produced byNisshoku Techno Fine Chemical Co., Ltd.), 25.6 g (160 mmol) of2,6-dihydroxynaphthalene (reagent produced by Tokyo Chemical IndustryCo., Ltd.) and 100 mL of 1,4-dioxane (reagent produced by Kanto ChemicalCo., Inc.), and 3.9 g (21 mmol) of p-toluenesulfonic acid (reagentproduced by Kanto Chemical Co., Inc.) was added thereto to prepare areaction liquid. The reaction liquid was stirred at 90° C. for 6 hoursto perform a reaction. Then, a neutralization treatment was performed bya 24% aqueous sodium hydroxide solution (reagent produced by KantoChemical Co., Inc.), the reaction liquid was concentrated, 50 g ofn-heptane (reagent produced by Kanto Chemical Co., Inc.) was addedthereto to precipitate a reaction product, and the resultant was cooledto room temperature followed by filtration for separation. A solidobtained by filtration was dried, and thereafter separated and purifiedby column chromatography to thereby provide 4.2 g of an objectivecompound (CAX-1) represented by the following formula.

Herein, the following peaks were observed by 400 MHz-¹H-NMR, and it wasconfirmed that the compound had a chemical structure of the followingformula.

¹H-NMR: (d-DMSO, internal standard TMS)

δ (ppm) 9.9 (2H, O—H), 7.0-8.3 (17H, Ph-H), 6.2 (1H, C—H), 4.2 (2H,CH₂), 1.2 (3H, CH₃)

As a result of organic element analysis, the carbon concentration andthe oxygen concentration of the resulting compound (CAX-1) were 82.8%and 9.4%, respectively.

The molecular weight of the resulting compound was measured by the abovemethod, and as a result, it was 508.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting compound (CAX-1) was 400° C. orhigher. Therefore, the compound was evaluated to have a high heatresistance and be applicable to high-temperature baking.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 10% by weight or more (Evaluation A) and compound (CAX-1)was evaluated to have an excellent solubility. Therefore, compound(CAX-1) was evaluated to have a high storage stability in a solutionstate and also be sufficiently applicable to an edge bead rinse liquid(mixed liquid of PGME/PGMEA) widely used in a semiconductormicrofabrication process.

(Synthesis Example 2) Synthesis of CAX-2

A container having an inner volume of 200 mL, equipped with a stirrer, acondenser and a burette, was prepared. To this container were charged17.8 g (80 mmol) of N-ethylcarbazole-3-carbaldehyde (produced byNisshoku Techno Fine Chemical Co., Ltd.), 25.6 g (160 mmol) of2,7-dihydroxynaphthalene (reagent produced by Tokyo Chemical IndustryCo., Ltd.) and 150 mL of 1,4-dioxane (reagent produced by Kanto ChemicalCo., Inc.), and 7.8 g (42 mmol) of p-toluenesulfonic acid (reagentproduced by Kanto Chemical Co., Inc.) was added thereto to prepare areaction liquid. The reaction liquid was stirred at 90° C. for 6 hoursto perform a reaction. Then, a neutralization treatment was performed bya 24% aqueous sodium hydroxide solution (reagent produced by KantoChemical Co., Inc.), the reaction liquid was concentrated, 50 g ofn-heptane (reagent produced by Kanto Chemical Co., Inc.) was addedthereto to precipitate a reaction product, and the resultant was cooledto room temperature followed by filtration for separation. A solidobtained by filtration was dried, and thereafter separated and purifiedby column chromatography to thereby provide 3.8 g of an objectivecompound (CAX-2) represented by the following formula.

Herein, the following peaks were observed by 400 MHz-¹H-NMR, and it wasconfirmed that the compound had a chemical structure of the followingformula.

¹H-NMR: (d-DMSO, internal standard TMS)

δ (ppm) 9.9 (2H, O—H), 7.0-8.1 (17H, Ph-H), 6.1 (1H, C—H), 4.4 (2H,CH₂), 1.3 (3H, CH₃)

As a result of organic element analysis, the carbon concentration andthe oxygen concentration of the resulting compound (CAX-2) were 82.8%and 9.4%, respectively.

The molecular weight of the resulting compound was measured by the abovemethod, and as a result, it was 508.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting compound (CAX-2) was 400° C. orhigher. The compound was evaluated to have a high heat resistance and beapplicable to high-temperature baking.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 5% by weight or more (Evaluation B) and compound (CAX-2)was evaluated to have an excellent solubility.

(Synthesis Example 3) Synthesis of CAX-3

A container having an inner volume of 200 mL, equipped with a stirrer, acondenser and a burette, was prepared. To this container were charged17.8 g (80 mmol) of N-ethylcarbazole-3-carbaldehyde (produced byNisshoku Techno Fine Chemical Co., Ltd.), 29.8 g (160 mmol) of4,4′-biphenol (reagent produced by Tokyo Chemical Industry Co., Ltd.)and 100 mL of γ-butyrolactone (reagent produced by Kanto Chemical Co.,Inc.), and 7.8 g (42 mmol) of p-toluenesulfonic acid (reagent producedby Kanto Chemical Co., Inc.) was added thereto to prepare a reactionliquid. The reaction liquid was stirred at 100° C. for 8 hours toperform a reaction. Then, a neutralization treatment was performed by a24% aqueous sodium hydroxide solution (reagent produced by KantoChemical Co., Inc.), the reaction liquid was concentrated, 100 g ofion-exchange water was added thereto to precipitate a reaction product,and the resultant was cooled to room temperature followed by filtrationfor separation. A solid obtained by filtration was dried, and thereafterseparated and purified by column chromatography to thereby provide 4.8 gof an objective compound (CAX-3) represented by the following formula.

Herein, the following peaks were observed by 400 MHz-¹H-NMR, and it wasconfirmed that the compound had a chemical structure of the followingformula.

¹H-NMR: (d-DMSO, internal standard TMS)

δ (ppm) 9.4 (4H, O—H), 6.8-7.8 (14H, Ph-H), 6.1 (1H, C—H), 4.2 (2H,CH₂), 1.2 (3H, CH₃)

As a result of organic element analysis, the carbon concentration andthe oxygen concentration of the resulting compound (CAX-3) were 81.0%and 11.0%, respectively.

The molecular weight of the resulting compound was measured by the abovemethod, and as a result, it was 577.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting compound (CAX-3) was 400° C. orhigher. The compound was evaluated to have a high heat resistance and beapplicable to high-temperature baking.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 10% by weight or more (Evaluation A) and compound (CAX-3)was evaluated to have an excellent solubility. Therefore, compound(CAX-3) was evaluated to have a high storage stability in a solutionstate and also be sufficiently applicable to an edge bead rinse liquid(mixed liquid of PGME/PGMEA) widely used in a semiconductormicrofabrication process.

(Synthesis Example 4) Synthesis of CAX-4

A container having an inner volume of 300 mL, equipped with a stirrer, acondenser and a burette, was prepared. To this container were charged19.8 g (80 mmol) of N-butylcarbazole-3-carbaldehyde (produced byNisshoku Techno Fine Chemical Co., Ltd.), 25.6 g (160 mmol) of2,6-dihydroxynaphthalene (reagent produced by Tokyo Chemical IndustryCo., Ltd.) and 100 mL of 1,4-dioxane (reagent produced by Kanto ChemicalCo., Inc.), and 3.9 g (21 mmol) of p-toluenesulfonic acid (reagentproduced by Kanto Chemical Co., Inc.) was added thereto to prepare areaction liquid. The reaction liquid was stirred at 90° C. for 6 hoursto perform a reaction. Then, a neutralization treatment was performed bya 24% aqueous sodium hydroxide solution (reagent produced by KantoChemical Co., Inc.), the reaction liquid was concentrated, 50 g ofn-heptane (reagent produced by Kanto Chemical Co., Inc.) was addedthereto to precipitate a reaction product, and the resultant was cooledto room temperature followed by filtration for separation. A solidobtained by filtration was dried, and thereafter separated and purifiedby column chromatography to thereby provide 4.2 g of an objectivecompound (CAX-4) represented by the following formula.

Herein, the following peaks were observed by 400 MHz-¹H-NMR, and it wasconfirmed that the compound had a chemical structure of the followingformula.

¹H-NMR: (d-DMSO, internal standard TMS)

δ (ppm) 9.9 (2H, O—H), 7.0-8.2 (17H, Ph-H), 6.1 (1H, C—H), 3.9-4.3 (6H,CH₂), 1.2 (3H, CH₃)

As a result of organic element analysis, the carbon concentration andthe oxygen concentration of the resulting compound (CAX-4) were 82.9%and 8.9%, respectively.

The molecular weight of the resulting compound was measured by the abovemethod, and as a result, it was 535.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting compound (CAX-4) was 400° C. orhigher. The compound was evaluated to have a high heat resistance and beapplicable to high-temperature baking.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 10% by weight or more (Evaluation A) and compound (CAX-4)was evaluated to have an excellent solubility. Therefore, compound(CAX-4) was evaluated to have a high storage stability in a solutionstate and also be sufficiently applicable to an edge bead rinse liquid(mixed liquid of PGME/PGMEA) widely used in a semiconductormicrofabrication process.

(Synthesis Example 5) Synthesis of CAX-5

A container having an inner volume of 300 mL, equipped with a stirrer, acondenser and a burette, was prepared. To this container were charged15.6 g (80 mmol) of 9H-carbazole-1-carbaldehyde (synthesized withreference to Tetrahedron; vol. 67; nb.32; (2011); p. 5725-5731), 25.6 g(160 mmol) of 2,6-dihydroxynaphthalene (reagent produced by TokyoChemical Industry Co., Ltd.) and 100 mL of 1,4-dioxane (reagent producedby Kanto Chemical Co., Inc.), and 3.9 g (21 mmol) of p-toluenesulfonicacid (reagent produced by Kanto Chemical Co., Inc.) was added thereto toprepare a reaction liquid. The reaction liquid was stirred at 90° C. for6 hours to perform a reaction. Then, a neutralization treatment wasperformed by a 24% aqueous sodium hydroxide solution (reagent producedby Kanto Chemical Co., Inc.), the reaction liquid was concentrated, 50 gof n-heptane (reagent produced by Kanto Chemical Co., Inc.) was addedthereto to precipitate a reaction product, and the resultant was cooledto room temperature followed by filtration for separation. A solidobtained by filtration was dried, and thereafter separated and purifiedby column chromatography to thereby provide 2.4 g of an objectivecompound (CAX-5) represented by the following formula.

Herein, the following peaks were observed by 400 MHz-¹H-NMR, and it wasconfirmed that the compound had a chemical structure of the followingformula.

¹H-NMR: (d-DMSO, internal standard TMS)

δ (ppm) 9.7-9.9 (2H, O—H), 10.9 (1H, N—H), 7.0-7.9 (16H, Ph-H), 6.0 (1H,C—H)

As a result of organic element analysis, the carbon concentration andthe oxygen concentration of the resulting compound (CAX-5) were 80.0%and 12.9%, respectively.

The molecular weight of the resulting compound was measured by the abovemethod, and as a result, it was 495.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting compound (CAX-5) was 400° C. orhigher. The compound was evaluated to have a high heat resistance and beapplicable to high-temperature baking.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 10% by weight or more (Evaluation A) and compound (CAX-5)was evaluated to have an excellent solubility. Therefore, compound(CAX-5) was evaluated to have a high storage stability in a solutionstate and also be sufficiently applicable to an edge bead rinse liquid(mixed liquid of PGME/PGMEA) widely used in a semiconductormicrofabrication process.

(Synthesis Example 6) Synthesis of CAX-6

A container having an inner volume of 300 mL, equipped with a stirrer, acondenser and a burette, was prepared. To this container were charged18.0 g (80 mmol) of 1-methoxy-9H-carbazole-3-carbaldehyde (murrayanine;synthesized with reference to Knolker, H.-J.; Bauermeister, M. J. Chem.Soc. Chem. Commun. 1990, 664.), 25.6 g (160 mmol) of2,6-dihydroxynaphthalene (reagent produced by Tokyo Chemical IndustryCo., Ltd.) and 100 mL of 1,4-dioxane (reagent produced by Kanto ChemicalCo., Inc.), and 3.9 g (21 mmol) of p-toluenesulfonic acid (reagentproduced by Kanto Chemical Co., Inc.) was added thereto to prepare areaction liquid. The reaction liquid was stirred at 90° C. for 6 hoursto perform a reaction. Then, a neutralization treatment was performed bya 24% aqueous sodium hydroxide solution (reagent produced by KantoChemical Co., Inc.), the reaction liquid was concentrated, 50 g ofn-heptane (reagent produced by Kanto Chemical Co., Inc.) was addedthereto to precipitate a reaction product, and the resultant was cooledto room temperature followed by filtration for separation. A solidobtained by filtration was dried, and thereafter separated and purifiedby column chromatography to thereby provide 2.4 g of an objectivecompound (CAX-6) represented by the following formula.

Herein, the following peaks were observed by 400 MHz-¹H-NMR, and it wasconfirmed that the compound had a chemical structure of the followingformula.

¹H-NMR: (d-DMSO, internal standard TMS)

δ (ppm) 9.9 (2H, O—H), 11.3 (1H, N—H), 7.0-7.9 (16H, Ph-H), 6.0 (1H,C—H), 1.5 (3H, CH₃)

As a result of organic element analysis, the carbon concentration andthe oxygen concentration of the resulting compound (CAX-6) were 80.1%and 12.5%, respectively.

The molecular weight of the resulting compound was measured by the abovemethod, and as a result, it was 509.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting compound (CAX-6) was 400° C. orhigher. The compound was evaluated to have a high heat resistance and beapplicable to high-temperature baking.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 10% by weight or more (Evaluation A) and compound (CAX-6)was evaluated to have an excellent solubility. Therefore, compound(CAX-6) was evaluated to have a high storage stability in a solutionstate and also be sufficiently applicable to an edge bead rinse liquid(mixed liquid of PGME/PGMEA) widely used in a semiconductormicrofabrication process.

(Synthesis Example 7) Synthesis of CAX-7

A container having an inner volume of 300 mL, equipped with a stirrer, acondenser and a burette, was prepared. To this container were charged15.6 g (80 mmol) of 2-hydroxy-9H-carbazole-1-carbaldehyde (synthesizedwith reference to Francisco, Caria S.; Rodrigues, Ligia R.; Cerqueira,Nuno M. F. S. A.; Oliveira-campos, Ana M. F.; Rodrigues, Ligia M.;Esteves, Ana P.; Bioorganic and Medicinal Chemistry; vol. 21; nb. 17;(2013); p. 5047-5053), 25.6 g (160 mmol) of 2,6-dihydroxynaphthalene(reagent produced by Tokyo Chemical Industry Co., Ltd.) and 100 mL of1,4-dioxane (reagent produced by Kanto Chemical Co., Inc.), and 3.9 g(21 mmol) of p-toluenesulfonic acid (reagent produced by Kanto ChemicalCo., Inc.) was added thereto to prepare a reaction liquid. The reactionliquid was stirred at 90° C. for 8 hours to perform a reaction. Then, aneutralization treatment was performed by a 24% aqueous sodium hydroxidesolution (reagent produced by Kanto Chemical Co., Inc.), the reactionliquid was concentrated, 100 g of n-heptane (reagent produced by KantoChemical Co., Inc.) was added thereto to precipitate a reaction product,and the resultant was cooled to room temperature followed by filtrationfor separation. A solid obtained by filtration was dried, and thereafterseparated and purified by column chromatography to thereby provide 2.9 gof an objective compound (CAX-7) represented by the following formula.

Herein, the following peaks were observed by 400 MHz-¹H-NMR, and it wasconfirmed that the compound had a chemical structure of the followingformula.

¹H-NMR: (d-DMSO, internal standard TMS)

δ (ppm) 9.4-9.6 (3H, O—H), 11.2 (1H, N—H), 7.0-7.9 (16H, Ph-H), 6.0 (1H,C—H)

As a result of organic element analysis, the carbon concentration andthe oxygen concentration of the resulting compound (CAX-7) were 80.0%and 12.9%, respectively.

The molecular weight of the resulting compound was measured by the abovemethod, and as a result, it was 495.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting compound (CAX-7) was 400° C. orhigher. The compound was evaluated to have a high heat resistance and beapplicable to high-temperature baking.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 10% by weight or more (Evaluation A) and compound (CAX-7)was evaluated to have an excellent solubility. Therefore, compound(CAX-7) was evaluated to have a high storage stability in a solutionstate and also be sufficiently applicable to an edge bead rinse liquid(mixed liquid of PGME/PGMEA) widely used in a semiconductormicrofabrication process.

(Synthesis Example 8) Synthesis of Resin (CAR-1)

A four-neck flask having a bottom outlet and an inner volume of 1 L,equipped with a Dimroth condenser, a thermometer and a stirring bladewas prepared. To this four-neck flask were charged 35.6 g (70 mmol,produced by Mitsubishi Gas Chemical Company, Inc.) of CAX-1 obtained inSynthesis Example 1, 21.0 g (280 mmol as formaldehyde, produced byMitsubishi Gas Chemical Company, Inc.) of a 40% by mass aqueous formalinsolution and 0.97 mL of 98% by mass sulfuric acid (produced by KantoChemical Co., Inc.) under a nitrogen stream, and allowed the reaction torun under ordinary pressure for 7 hours with refluxing at 100° C.Thereafter, 180.0 g of o-xylene (special grade chemical, produced byWako Pure Chemical Industries, Ltd.) as a dilution solvent was added tothe reaction liquid and left to stand, and then an aqueous phase being abottom phase was removed. Furthermore, the resultant was neutralized andwashed with water, and o-xylene was distilled off under reducedpressure, thereby providing 38.2 g of a resin (CAR-1) as a brown solid.

In the resulting resin (CAR-1), Mn was 1885, Mw was 4220 and Mw/Mn was2.24. In addition, the carbon concentration was 79.8% by mass, and theoxygen concentration was 8.5% by mass.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting resin (CAR-1) was 350° C. orhigher and lower than 400° C. Therefore, the resin was evaluated to beapplicable to high-temperature baking.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 10% by weight or more (Evaluation A) and the resin(CAR-1) was evaluated to have an excellent solubility.

(Synthesis Example 9) Synthesis of Resin (CAR-2)

A four-neck flask having a bottom outlet and an inner volume of 1 L,equipped with a Dimroth condenser, a thermometer and a stirring bladewas prepared. To this four-neck flask were charged 35.6 g (70 mmol,produced by Mitsubishi Gas Chemical Company, Inc.) of CAX-1 obtained inSynthesis Example 1, 50.9 g (280 mmol, produced by Mitsubishi GasChemical Company, Inc.) of 4-biphenylaldehyde, 100 mL of anisole(produced by Kanto Chemical Co., Inc.) and 10 mL of oxalic aciddihydrate (produced by Kanto Chemical Co., Inc.) under a nitrogenstream, and allowed the reaction to run under ordinary pressure for 7hours with refluxing at 100° C. Thereafter, 180.0 g of o-xylene (specialgrade chemical, produced by Wako Pure Chemical Industries, Ltd.) as adilution solvent was added to the reaction solution and left to stand,and then an aqueous phase being a bottom phase was removed. Furthermore,the resultant was neutralized and washed with water, and the solvent andthe unreacted 4-biphenylaldehyde in the organic phase were distilled offunder reduced pressure, thereby providing 38.2 g of a resin (CAR-2) as abrown solid.

In the resulting resin (CAR-2), Mn was 2382, Mw was 4610 and Mw/Mn was1.93. In addition, the carbon concentration was 82.8% by mass, and theoxygen concentration was 7.5% by mass.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting resin (CAR-2) was 350° C. orhigher and lower than 400° C. Therefore, the resin was evaluated to beapplicable to high-temperature baking.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 10% by weight or more (Evaluation A) and the resin(CAR-2) was evaluated to have an excellent solubility.

(Comparative Synthesis Example 1)

A four-neck flask having a bottom outlet and an inner volume of 10 L,equipped with a Dimroth condenser, a thermometer and a stirring bladewas prepared. To this four-neck flask were charged 1.09 kg (7 mol,produced by Mitsubishi Gas Chemical Company, Inc.) of1,5-dimethylnaphthalene, 2.1 kg (28 mol as formaldehyde, produced byMitsubishi Gas Chemical Company, Inc.) of a 40% by mass aqueous formalinsolution and 0.97 mL of 98% by mass sulfuric acid (produced by KantoChemical Co., Inc.) under a nitrogen stream, and allowed the reaction torun under ordinary pressure for 7 hours with refluxing at 100° C.Thereafter, ethylbenzene (special grade chemical, produced by Wako PureChemical Industries, Ltd.) (1.8 kg) as a dilution solvent was added tothe reaction solution and left to stand, and then an aqueous phase beinga bottom phase was removed. Furthermore, the resultant was neutralizedand washed with water, and ethylbenzene and the unreacted1,5-dimethylnaphthalene were distilled off under reduced pressure,thereby providing 1.25 kg of a dimethylnaphthalene formaldehyde resin asa light-brown solid.

With respect to the molecular weight of the resultingdimethylnaphthalene formaldehyde, Mn was 562, Mw was 1168 and Mw/Mn was2.08. In addition, the carbon concentration was 84.2% by mass, and theoxygen concentration was 8.3% by mass.

Subsequently, a four-neck flask having an inner volume of 0.5 L,equipped with a Dimroth condenser, a thermometer and a stirring blade,was prepared. To this four-neck flask were charged 100 g (0.51 mol) ofthe dimethylnaphthalene formaldehyde resin obtained as described aboveand 0.05 g of paratoluenesulfonic acid under a nitrogen stream, heatedfor 2 hours with the temperature being raised to 190° C., and thenstirred. Thereafter, 52.0 g (0.36 mol) of 1-naphthol was further addedthereto, and further heated to 220° C. to allow the reaction to run for2 hours. After being diluted with a solvent, the resultant wasneutralized and washed with water, and the solvent was removed underreduced pressure to thereby provide 126.1 g of a modified resin (CR-1)as a blackish brown solid.

With respect to the resulting resin (CR-1), Mn was 885, Mw was 2220 andMw/Mn was 4.17. In addition, the carbon concentration was 89.1% by massand the oxygen concentration was 4.5% by mass.

As a result of thermogravimetric measurement (TG), the 10% thermalweight loss temperature of the resulting resin (CR-1) was less than 350°C. Therefore, the resin was evaluated to have difficulty in applicationto high-temperature baking where high etching resistance and heatresistance were required.

As a result of evaluation of the solubility in PGME and PGMEA, thesolubility was 10% by weight or more (Evaluation A) and the resin (CR-1)was evaluated to have an excellent solubility.

(Examples 1 to 9 and Comparative Example 1)

Each composition for forming an underlayer film for lithography wasprepared so that each composition shown in Table 1 was achieved. Thatis, the following materials were used.

Acid generating agent: di-tert-butyldiphenyliodoniumnonafluoromethanesulfonate (DTDPI) produced by Midori Kagaku Co., Ltd.

Crosslinking agent: Nikalac MX270 (Nikalac) produced by Sanwa ChemicalCo., Ltd.

Organic solvent: propylene glycol monomethyl ether acetate (PGMEA)

Novolac: PSM4357 produced by Gun Ei Chemical Industry Co., Ltd.

Then, each composition for forming an underlayer film was spin-coated ona silicon substrate, thereafter baked at 240° C. for 60 seconds andfurther at 400° C. for 120 seconds to prepare each underlayer filmhaving a film thickness of 200 nm.

An etching test was performed under conditions shown below to evaluateetching resistance. The evaluation results are shown in Table 1.

[Etching Test]

Etching apparatus: RIE-10NR manufactured by Samco Inc.

Output: 50 W

Pressure: 20 Pa

Time: 2 min

Etching Gas

Ar gas flow rate:CF₄ gas flow rate:O₂ gas flow rate=50:5:5 (sccm)

[Evaluation of Etching Resistance]

The evaluation of etching resistance was performed according to thefollowing procedure.

First, an underlayer film of novolac was prepared under the sameconditions as those in Example 1 except that novolac (PSM4357 producedby Gunei Chemical Industry Co., Ltd.) was used instead of the compound(CAX-1) used in Example 1. Then, the etching test was performed withrespect to the underlayer film of novolac as a subject, and the etchingrate in that time was measured.

Then, the etching resistances were evaluated according to the followingcriteria based on the etching rate of the underlayer film of novolac.

<Evaluation Criteria>

A; etching rate of less than −10% compared with the underlayer film ofnovolac

B; etching rate of −10% to +5% compared with underlayer film of novolac

C; etching rate of more than +5% compared with the underlayer film ofnovolac

TABLE 1 Material Acid Cross- for forming Organic generating linkingunderlayer solvent agent agent Evaluation film (parts (parts (parts(parts of etching by mass) by mass) by mass) by mass) resistance Example1 CAX-1 PGMEA DTDPI Nikalac A (10) (90) (0.5) (0.5) Example 2 CAX-2PGMEA DTDPI Nikalac A (10) (90) (0.5) (0.5) Example 3 CAX-3 PGMEA DTDPINikalac A (10) (90) (0.5) (0.5) Example 4 CAX-4 PGMEA DTDPI Nikalac B(10) (90) (0.5) (0.5) Example 5 CAX-5 PGMEA DTDPI Nikalac A (10) (90)(0.5) (0.5) Example 6 CAX-6 PGMEA DTDPI Nikalac A (10) (90) (0.5) (0.5)Example 7 CAX-7 PGMEA DTDPI Nikalac A (10) (90) (0.5) (0.5) Example 8CAR-1 PGMEA DTDPI Nikalac B (10) (90) (0.5) (0.5) Example 9 CAR-2 PGMEADTDPI Nikalac B (10) (90) (0.5) (0.5) Compar- CR-1 PGMEA DTDPI Nikalac Cative (10) (90) (0.5) (0.5) Example 1

Example 10

Then, the composition for forming an underlayer film for lithography inExample 1 was coated on a SiO₂ substrate having a film thickness of 300nm, and baked at 240° C. for 60 seconds and further at 400° C. for 120seconds to thereby form an underlayer film having a film thickness of 70nm. A resist solution for ArF was coated on the underlayer film, andbaked at 130° C. for 60 seconds to thereby form a photoresist layerhaving a film thickness of 140 nm.

Herein, as the resist solution for ArF, one prepared by blending 5 partsby mass of the compound of the following formula (11), 1 part by mass oftriphenylsulfonium nonafluoromethanesulfonate, 2 parts by mass oftributylamine, and 92 parts by mass of PGMEA was used.

A compound of formula (11) was prepared as follows. That is, 4.15 g of2-methyl-2-methacryloyloxyadamantane, 3.00 g ofmethacryloyloxy-γ-butyrolactone, 2.08 g of 3-hydroxy-1-adamantylmethacrylate and 0.38 g of azobisisobutyronitrile were dissolved in 80mL of tetrahydrofuran to provide a reaction solution. This reactionsolution was subjected to polymerization under a nitrogen atmosphere for22 hours with the reaction temperature being kept at 63° C., andthereafter the reaction solution was dropped in 400 mL of n-hexane. Aproduct resin thus obtained was solidified and purified, and a whitepowder produced was taken by filtration and dried under reduced pressureat 40° C. overnight to provide a compound represented by the followingformula.

In the formula (11), the numerals 40, 40, and 20 indicate theproportions of the respective constituent units, and do not mean a blockcopolymer.

Then, the photoresist layer was exposed by using an electron beamlithography apparatus (ELS-7500, produced by Elionix, Inc., 50 keV),baked at 115° C. for 90 seconds (PEB), and developed with a 2.38% bymass aqueous tetramethylammonium hydroxide (TMAH) solution for 60seconds, thereby providing a positive-type resist pattern.

(Comparative Example 2)

Except that no underlayer film was formed, the same manner as in Example7 was performed to form a photoresist layer directly on a SiO₂ substrateto provide a positive-type resist pattern.

[Evaluation]

The shapes of the resist patterns of 40 nm L/S (1:1) and 80 nm L/S (1:1)provided in each of Example 10 and Comparative Example 2 were observedby using an electron microscope (S-4800) manufactured by Hitachi Ltd. Acase where the shape of the resist pattern after development had nopattern collapse and had good rectangularity was evaluated to be goodand a case the shape had pattern collapse and did not have goodrectangularity was evaluated to be poor. In the observation results, theminimum line width where there was no pattern collapse andrectangularity was good was defined as the resolution and used as anevaluation index. Furthermore, the minimum amount of electron beamenergy, where a good pattern shape could be drawn, was defined as thesensitivity and used as an evaluation index. The results are shown inTable 2.

TABLE 2 Material for Resist pattern forming under- ResolutionSensitivity formation after layer film (nmL/S) (μC/cm²) developmentExample 10 Material 40 20 Good described in Example 1 Comparative Notused 90 38 Poor Example 2

As can be seen from Table 2, it was confirmed that the underlayer filmobtained in Example 10 was significantly excellent in resolution andsensitivity as compared with that in Comparative Example 2. It was alsoconfirmed that the resist pattern shape after development had no patterncollapse and had good rectangularity. Furthermore, it was shown from thedifference in the resist pattern shape after development that thematerial for forming an underlayer film for lithography in Example 1 hadgood adhesiveness with a resist material.

(Example 11) Purification of CAX-1

To a four-neck flask (bottom outlet type) having a volume of 1000 mL wascharged 300 g of a solution (5% by mass) in which CAX-1 obtained inExample 1 was dissolved in PGMEA, and heated to 80° C. with stirring.Then, 74 g of an aqueous oxalic acid solution (pH: 1.3) was addedthereto, stirred for 5 minutes and thereafter left to stand for 30minutes. The resultant was thus separated to an oil phase and an aqueousphase, and therefore the aqueous phase was removed. Such an operationwas repeated once, and thereafter the resulting oil phase was chargedwith 74 g of ultrapure water, stirred for 5 minutes and thereafter leftto stand for 30 minutes to remove the aqueous phase. Such an operationwas repeated three times, and thereafter the flask was subjected topressure reduction to 200 hPa or less while being heated to 80° C., tothereby allow the remaining water content and PGMEA to be distilled offby concentration. Thereafter, dilution with PGMEA (EL grade, reagentproduced by Kanto Chemical Co., Inc.) was made to adjust theconcentration to 10% by mass, thereby providing a solution of CAX-1having a reduced metal content, in PGMEA.

The contents of various metals were measured by ICP-MS with respect tothe 10% by mass CAX-1 solution in PGMEA before treatment, and thesolution obtained in Example 11. The measurement results are shown inTable 3.

TABLE 3 Metal content (ppb) Na Mg K Fe Cr Sn Before treatment >9923.2 >99 >99 10.7 13.6 CAX-1 Example 11 0.7 0.9 0.6 1.2 1.3 1.4

The compound and the resin of the present invention have a relativelyhigh heat resistance and also a relatively high solvent solubility, andwhich can be applied to a wet process. Therefore, a material for formingan underlayer film for lithography and an underlayer film, using thecompound or the resin of the present invention, can be widely andeffectively utilized in various applications in which these propertiesare required. Therefore, the present invention can be widely andeffectively utilized for, for example, a coating agent for asemiconductor, a resist resin for a semiconductor, and a resin forforming an underlayer film. In particular, the present invention can beparticularly effectively utilized in the field of an underlayer film forlithography and an underlayer film for a multilayer resist.

The invention claimed is:
 1. A material for forming an underlayer filmfor lithography comprising a compound represented by the followingformula (1-4):

wherein each R¹ is independently selected from the group consisting of ahydrogen atom, a halogen group, a nitro group, an amino group, ahydroxyl group, an alkyl group having 1 to 30 carbon atoms, an alkenylgroup having 2 to 30 carbon atoms, an aryl group having 6 to 40 carbonatoms and combinations thereof, in which the alkyl group, the alkenylgroup and the aryl group may have an ether bond, a ketone bond or anester bond, and each q is independently an integer of 0 to
 4. 2. Thematerial for forming an underlayer film for lithography according toclaim 1, wherein the compound represented by the formula (1-4) is acompound represented by the following formula (CAX-1):


3. A composition for forming an underlayer film for lithography,comprising the material for forming an underlayer film for lithographyaccording to claim 1, and a solvent.
 4. The composition for forming theunderlayer film for lithography according to claim 3, further comprisingan acid generating agent.
 5. The composition for forming the underlayerfilm for lithography according to claim 3, further comprising acrosslinking agent.
 6. An underlayer film for lithography, formed fromthe composition for forming the underlayer film for lithographyaccording to claim
 3. 7. A resist pattern forming method comprising step(A-1) of forming an underlayer film on a substrate by using thecomposition for forming the underlayer film for lithography according toclaim 3, step (A-2) of forming at least one photoresist layer on theunderlayer film, and step (A-3) of, after step (A-2), irradiating apredetermined region of the photoresist layer with radiation, followedby developing.
 8. A circuit pattern forming method comprising step (B-1)of forming an underlayer film on a substrate by using the compositionfor forming the underlayer film for lithography according to claim 3,step (B-2) of forming an intermediate layer film on the underlayer filmby using a silicon atom-containing resist intermediate layer filmmaterial, step (B-3) of forming at least one photoresist layer on theintermediate layer film, step (B-4) of, after step (B-3), irradiating apredetermined region of the photoresist layer with radiation, followedby developing to form a resist pattern, and step (B-5) of, after step(B-4), etching the intermediate layer film with the resist pattern as amask, etching the underlayer film with the obtained intermediate layerfilm pattern as an etching mask and etching the substrate with theobtained underlayer film pattern as an etching mask, to form a patternon the substrate.
 9. A method for purifying the compound used in thematerial for forming an underlayer film for lithography according toclaim 1, the method comprising a step of bringing a solution comprisingan organic solvent optionally immiscible with water and the compound orthe resin into contact with an acidic aqueous solution for extraction.10. The method according to claim 9, wherein the acidic aqueous solutionis an aqueous solution of at least one mineral acid selected from thegroup consisting of hydrochloric acid, sulfuric acid, nitric acid andphosphoric acid, or an aqueous solution of at least one organic acidselected from the group consisting of acetic acid, propionic acid,oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid,tartaric acid, citric acid, methanesulfonic acid, phenolsulfonic acid,p-toluenesulfonic acid and trifluoroacetic acid.
 11. The methodaccording to claim 9, wherein the organic solvent optionally immisciblewith water is toluene, 2-heptanone, cyclohexanone, cyclopentanone,methyl isobutyl ketone, propylene glycol monomethyl ether acetate,1,2-diethoxyketone, butyl acetate or ethyl acetate.
 12. A resin having astructure represented by the following formula (1-4):

wherein each R¹ is independently selected from the group consisting of ahydrogen atom, a halogen group, a nitro group, an amino group, ahydroxyl group, an alkyl group having 1 to 30 carbon atoms, an alkenylgroup having 2 to 30 carbon atoms, an aryl group having 6 to 40 carbonatoms and combinations thereof, in which the alkyl group, the alkenylgroup and the aryl group may have an ether bond, a ketone bond or anester bond, and each q is independently an integer of 0 to 4.